welcome to the GED science course from Ultimate ged.com this is a complete course designed to help you easily pass the GED please watch the full video because we cover everything you need to pass you can also get our full GED math course with over 250 step-by-step videos at ultimate ged.com the scientific method and introduction to GED graphs read the passage and graph and answer the questions below a group of scientists wants to study the effect of temperature on the hatching of turtle eggs they collect turtle eggs from a beach and incubate them at different temperatures to see if there is a correlation between temperature and the time it takes for the eggs to hatch their results are shown in the graph below question one which step of the scientific method involves collecting turtle eggs from a beach and incubating them at different temperatures a observation B hypothesis C experimentation D conclusion to answer questions like this you need to be familiar with the scientific method you can check out a full lesson on the scientific method on Ultimate ged.com the scientific method is a systematic approach used by scientists to investigate natural phenomena and acquire new knowledge the method involves making observations about a natural phenomenon forming an hypothesis that is formulating a testable explanation or prediction based on the observations designing and conducting experiments to test the hypothesis analyzing and interpreting the data obtained from the experiments and drawing a conclusion based on the results please note that there are different variations of these steps but the idea is always the same the most common one is the addition of communication as the last step for this question the correct answer is C experimentation this step involves designing and conducting experiments to test the hypothesis formulated in this case the scientists are manipulating the temperature of the eggs to determine if it has an effect on the time it takes for them to hatch question two what is the independent variable in the study of the effect of temperature on the hatching of turtle eggs a time to hatch B temperature C type of turtle D location of beach the correct answer is B temperature to be good in this section of the GED you must be able to identify the dependent and independent variables independent variables and dependent variables are two types of variables used in scientific investigations the independent variable is the variable that is manipulated or Changed by the experimentor to observe its effect on the dependent variable on the other hand the dependent variable is the variable that is being measured or observed and is affected by the independent variable in other words the independent variable is the cause or predictor of the outcome while the dependent variable is the effect or the outcome being measured for example in the study of the effect of temperature on the hatching of turtle eggs the independent variable is the temperature which is being manipulated by the experimenter while the dependent variable is the time it takes for the eggs to hatch which is being observed and measured the experimentor is interested in observing how changes in the independent variable temperature affect changes in the dependent variable time to hatch question three what conclusion can be drawn from the graph a higher temperatures result in Faster hatching times b lower temperatures result in Faster hatching times C there is no correlation between temperature and hatching time D more data is needed to draw a conclusion before we answer this question let's have a quick lesson on graphs you can learn more from Ultimate ged.com the title of the graph tells us what the graph is about the xaxis which is the horizontal axis is usually the independent variable so in question two we could have used the graph to answer it the Y AIS which is the vertical axis is usually the dependent variable graphs of this form are read from left to right the slope of the line determines if the line is increasing or decreasing for this graph we can say that there's a decrease in the time to hatch when the temperature increased from 25 to 27° and time to hatch continues to decrease as you increase the temperature this means our answer is a higher temperatures result in Faster hatching times question four based on the graph which temperature resulted in the shortest time to hatch a 25° C B 29° cus c 35° c d 31° cus the correct answer is C 35° the work here is to locate the point with the shortest time that point will be this then look for the temperature that corresponds to it that temperature is 35° please note that it's not always possible to get exact values on a graph you need to make your best guess for a point like this if we want to find the number of days the exact value has not been given we can estimate it to be 53 it's above 50 and below 60 lesson two units measurements and conversions question 5 a car is traveling at a speed of 60 MPH what is the speed of the car in kilom per hour a 96.5 4 kmph b 1 100 kmph C 120 kmph D 16.9 3 km per hour to pass the GED science it's important you know your conversions to convert miles per hour to kilm hour we can use the conversion factor 1 m equal 1.609 km this conversion factor will be given to you on the GED therefore to convert 60 m per hour to kilm per hour we can just multiply 60 by 1.609 this gives us a speed of approximately 96.5 4 kmph so the correct answer is a the table below shows the temperature in degrees fahren from Monday to Sunday of a small town on the East Coast use the table to answer the following question question six what was the temperature in degrees Cel for the highest temperature of the week a 3670 B 25.5 6 c 29.25 d 32.4 from the table the highest temperature of the week was 78° F this is in degre fah however we are supposed to calculate it in degrees Celsius the formula is stated above as temperature in de C equals temperature in de fit - 32 * 5 9 temperature in de C = 78 - 32 * 5 over 9 78 - 32 is 46 so we have 46 * 5 9 we can work this out on the calculator to get 25.5 6 the answer is therefore option b 25.5 6° lesson three properties of life and cellular biology question s which of the following is not one of the characteristics of living organisms a homeostasis B metabolism C reproduction D evolution the correct answer is evolution the seven characteristics are organization energy utilization homeostasis growth and development reproduction adaptation and response to stimuli check out ultimate ged.com for more on this question eight which of the following best describes the relationship between the character istics of living organisms and the properties of Life a the seven characteristics are distinct from the properties of Life B the seven characteristics are examples of the properties of Life C the seven characteristics are unrelated to the properties of Life D the properties of Life are only relevant to non-living matter the correct answer is B the seven characteristics are examples of the properties of life these properties of life and the characteristics of living organisms are often confused and mostly interchanged there is a difference the properties of life is what all living organism have the characteristics of living organism is how an individual living organism exhibit that property you can basically call it examples let's take the property of life that is metabolism wolf fish and birds have metabolism as a property of Life which refers to the chemical processes that occur within their body bodies to convert nutrients into energy and Carry Out life sustaining functions however fish and birds have different metabolic rates and processes due to their distinct Lifestyles and habitats fish are cold-blooded which means they cannot regulate their body temperature internally and instead rely on the temperature of their environment to regulate their metabolism as a result the metabolism slows down in colder temperatures and speeds up in warmer temperatures in contrast birds are warm-blooded which means they have the ability to regulate their body temperature internally through metabolism birds have a high metabolic rate to generate the heat required to maintain their body temperature which is typically higher than that of fish in summary both fish and birds have metabolism as a property of life but their metabolic rates and processes differ based on their distinct Lifestyles and habitats meaning their metabolism characteristics are different question n what is the name of the organel labeled X in the diagram a nucleus b lome c mitochondrian D endoplasmic reticulum the answer is a nucleus uni a working knowledge of plant and animal cells you should be able to identify and label the major organel this is an animal cell and here are the organel pause the video and go through it question 10 what is the function of the cell membrane a to store genetic information B to support the cell structure C to protect the cell from pathogens D to control the movement of substances into and out of the cell the correct answer is D to control the movement of substances into and out of the cell for the GED you are expected to know the functions of the organel please don't spend too much time memorizing them you just need a good idea of what they are the cell membrane is a thin flexible barrier that surrounds the cell its main function is to control the movement of substances into and out of the cell while also providing protection and support for the cell question 11 which of the following cell types is responsible for producing antibodies to fight infections a red blood cells B white blood cells C muscle cells D ner cells the correct answer is B white blood cells white blood cells cells also known as lucaites are responsible for producing antibodies to fight infections antibodies are proteins that recognize and bind to foreign substances such as viruses or bacteria and mark them for Destruction by other cells of the immune system red blood cells a do not have a nucleus and are not involved in immune responses they are responsible for carrying oxygen from the lungs to the body's tissues muscle cells C are specialized cells that are involved in movement and do not have a role in producing antibodies nerve cells D are specialized cells that are involved in transmitting signals throughout the body and do not have a role in producing antibodies Lesson Four genetics and heredity read the passage and answer the question below traits are inherited characteristics that are passed down from parents to offspring through genetic material some traits are controlled by a single Gene While others are influenced by multiple genes and environmental factors one example of a single Gene trait is the ability to roll your tongue which is determined by a single Gene with two possible versions or alals if an individual inherits at least one copy of the dominant alil for tongue rolling they will be able to roll their tongue however if they inherit two copies of the recessive alil they will not be able to roll their ton another example of a trait influenced by multiple genes and environmental factors is height while genes play a role in determining an individual's height factors such as nutrition and physical activity can also have an impact question 12 what is an example of a single Gene trait a eye color B height C skin tone D tongue rolling ability the correct answer is D tongue rolling ability the passage provides tongue rolling ability as an example of a single Gene trait that is determined by a single Gene with two possible versions or alals question 13 if one parent is heterozygous for ton rolling ability and the other parent is homozygous recessive for this trait what is the probability that their offspring will be able to roll their tongue a 0% B 25% C 50% D 75% the correct answer is C 50% since genetics is a very important topic on the GED science let's spend some time learning how we got the 50% when we talk about genetics we use the terms heterozygous homo zygous dominant and homozygous recessive to describe the different possible genotypes for this trait heterozygous refers to having two different alals for a particular Gene in the case of tongue rolling ability the dominant alil determines the ability to roll the tongue while the recessive alil results in the inability to roll the tongue therefore an individual who is heterozygous for tongue rolling ability would have the genotype indicating that they have one copy of the dominant alil and one copy of the recessive alil homozygous dominant refers to having two identical copies of the dominant alil in the case of Tong rolling ability an individual who is homozygous dominant would have the genotype indicating that they have two copies of the dominant alil and are able to roll their tongue homo zygas recessive refers to having two identical copies of the recessive alil in the case of tongue rolling ability an individual who is homozygous recessive would have the genotype indicating that they have two copies of the recessive alal and are unable to roll their tongue now let's use this information to answer the question if one parent is heterozygous for tongue rolling ability let's say the father and the other parent is homozygous recessive let's say the mother we can use a punet square to determine the possible genotypes and phenotypes of their offspring here is an example pet Square for this cross let's put the father's genotype here let's put the mother's genotype here you can interchange them it won't make a difference the first section will be the dominant R and recessive R we got that because of this R here and this R here we do that for the next section this and this will give us a dominant R and a recessive R we go to the third section we have two recessive R this is because of this R and this r then we fill up the last section same idea we have two recessive R if The Offspring is heterozygous or homozygous dominant they will be able to roll their tongue here we have two possibilities of heterozygous this is out of four total possibilities this is 2 over 4 which can be reduced to 1 over two this is the same as 50% lesson five Evolution and natural selection read the passage and answer the question below birds are a diverse group of animals that have evolved a wide range of adaptations in response to their environment one example of natural selection in Birds is the evolution of beak size and shape in the Galapagos Islands finches with different beak sizes and shap shapes have adapted to different food sources for example finches with longer narrower beaks are better adapted to feeding on insects while finches with shorter rer beaks are better adapted to cracking seeds during times of drought when food sources become scarce finches with beaks better suited to available food sources are more likely to survive and reproduce passing on their genes to the Next Generation over time this process can lead to the evolution of new species with distinct beak sizes and shapes question 14 what is natural selection and how does it contribute to Evolution a natural selection is the process by which individuals with certain traits are more likely to survive and reproduce than individuals without those traits B natural selection is the process by which individuals pass on their genetic material to the Next Generation C natural selection is the process by which individuals adapt to their environment D natural selection is the process by which individuals change over time in response to changes in their environment the correct answer is a natural selection is the process by which individuals with certain traits are more likely to survive and reproduce than individuals without those traits the passage defines natural selection as the process by which individuals with certain advantageous traits are more likely to survive and reproduce passing on their genes to the Next Generation over time this process can lead to the evolution of new species with distinct characteristics question 15 what is an example of natural selection in Birds a the evolution of flight feathers B the development of colorful plumage C the evolution of beak size and shape D the migration patterns of birds the correct answer answer is C the evolution of beak size and shape the passage describes the evolution of beak size and shape in finches as an example of an adaptation in birds that has occurred through natural selection question 16 how do finches with beaks better suited to available food sources during a drought contribute to evolutionary change a they are more likely to develop longer lifespans B they are more likely to mate with birds with similar beak sizes and shapes C they are more likely to survive and reproduce passing on their genes to the Next Generation D they are more likely to develop new adaptations that make them better suited to their environment the answer is C they are more likely to survive and reproduce passing on their genes to the Next Generation during times of drought when food sources become scarce finches with beaks better suited to available food sources are more likely to survive and reproduce this is because they are better able to obtain food which gives them a competitive advantage over finches with less suitable beaks as a result the genes that determine beak size and shape are more likely to be passed onto the Next Generation and the frequency of these genes in the population will increase over time this process is called natural selection and can lead to the evolution of new species with distinct beak sizes and shapes that are better adapted to their environment part two please watch the full video and all parts so you can cover all the topics you need to pass let's Dive Right In lesson six ecology and classification in a small grassland ecosystem a variety of organisms interact and depend on one another for survival at the base of the food chain grass absorbs sunlight and converts it into energy through photosynthesis serving as a primary source of nourishment for herbivores grasshoppers which are primary consumers feed on the grass obtaining energy and nutrients as secondary consumers frogs prey on the Grasshoppers transferring energy up the food chain in turn snakes tertiary consumers hunt frogs as their source of energy at the top of the food chain Hawks quaternary consumer tumors capture and consume snakes which are their primary prey this food chain demonstrates the interconnectedness of the grassland ecosystem as energy flows from one organism to another forming a cycle that supports life at all trophic levels the diagram shows this interaction question 17 which organism in the provided food chain is a primary consumer a grass B grasshopper C frog D snake the correct answer is B grasshopper please do not confuse the primary consumer with the producer the primary consumer is an organism that feeds directly on producers in this case the grass producers convert sunlight into energy through the process of photosynthesis and primary consumers consume these producers to obtain energy and nutrients question 18 in the grassland food chain mentioned earlier which organism is a secondary consumer a grass B grasshopper C frog D snake the correct answer is C frog in the grassland food chain the Frog prays on the grasshopper which is a primary consumer since the Frog obtains its energy and nutrients by feeding on the primary consumer it is considered a secondary consumer in the food chain question 19 what is the purpose of classification and taxonomy in biology a to identify and name new species B to understand the evolutionary history and relationships among organisms C to determine the geographic distribution of organisms D to study the physical characteristics of organisms the correct answer is B to understand the evolutionary history and relationships among organisms the purpose of classification and taxonomy and biology is to organize living organisms based on their evolutionary history and relationships to each other this allows scientists to better understand the diversity of life and how different species are related to each other question 20 match the following animals with their respective taxonomic classes sharks Penguins salamanders butterflies crocodiles for questions on taxonomy the animals used are usually going to be familiar animals start by matching the ones that are obvious to you and continue from there for this question sharks are a type of fish penguins are birds salamanders are amphibians butterflies are insects and crocodiles are reptiles during a field trip to a local pond students observed and identified various organisms belonging to different taxonomic groups the goal of the field trip was to understand the biodiversity and distribution of these organisms within the pond ecosystem after careful observation and documentation the students found that the pond was inhabited by 20% fish 30% amphibians 25% Birds and the rest were insects they decided to represent this data in the form of a pie chart to visualize the percentage of each taxonomic group present in the pond ecosystem based on this information answer the following questions question 21 according to the students observations at the pond which taxonomic group has the highest percentage of organisms in the pond ecosystem a fish B amphibians C Birds D insects the correct answer is B amphibians pie chats are another form of graphs that you need to be familiar with for the GED for this question you can just observe the pie chat and notice that the pi for the amphibians is the largest eyeballing is always your first option eyeballing might not work for values that are very close calculation is your second option to answer this question you need to know the percentage of organisms that are insects since that was not given in the passage a full pie chat represents 100% to get the percentage that are insects we will subtract 100 minus the percentage of fish which is 20 minus the percentage of amphibians which is 30 minus the percentage of birds which is 25 this will give us 25% as the percentage of insects now that we have all the percentage is we can see that the amphibians which is 30% is the highest question 22 if the students observed a total of 200 individual organisms during their field trip to the pond how many of these organisms were fish a 20 b 40 C 60 d 80 the correct answer answer is b 40 on a pie chat you can be given percentages or the actual values you should know how to convert between the two for this pie chat we are given the percentages this question is asking as to find the actual value of the fish to do this we have to find 20% of the total 200 since the percentage of fish is 20% 20% is the same as 20 over 100 of in math means multiplication then we have our 200 we can now work this calculation out to get 40 as our answer read the passage and answer the questions below in the tropical rainforest a diverse array of species exist in a complex food web at the base of the food chain are primary consumers such as insects and rodents which feed on plants and other vegetation these primary consumers are in turn eaten by secondary consumers such as birds and small mammals finally there are tertiary consumers such as large cats and snakes which feed on the secondary consumers each level of the food chain is important to maintain the balance of the ecosystem and changes in one level can have Ripple effects throughout the food web question 23 what is the primary source of food for primary consumers in the tropical rainforest ecosystem a other animals B rocks and minerals C sunlight D plants and other vegetation the correct answer is D plants and other vegetation the passage states that primary consumers in the tropical rainforest ecosystem feed on plants and other vegetation this is because they are herbivores meaning they obtain their energy and nutrients from consuming plants question 24 give an example of a tertiary consumer in the tropical rainforest ecosystem a a butterfly b a tucan c a Jaguar d a monkey the correct answer is c a Jaguar the passage states that tertiary consumers in the tropical rainforest ecosystem are animals that feed on secondary consumers Jaguars are an example of a tertiary consumer in this ecosystem as they primarily feed on smaller mammals such as monkeys deer and rodents question 25 what would happen if there were a sudden decrease in the population of primary consumers in the tropical rainforest ecosystem a the population of secondary consumers would increase B the population of secondary consumers would decrease C C the population of tertiary consumers would decrease D the ecosystem would not be affected the correct answer is B the population of secondary consumers would decrease the passage explains that each level of the food chain is important to maintaining the balance of the ecosystem and changes in one level can have Ripple effects throughout the food web if the population of primary consumers were to suddenly decrease there would be less food available for the secondary consumers that rely on them for food this would likely result in a decrease in the population of secondary consumers Choice C is also correct if you look at the Ripple effects but B is a better choice in this question lesson seven human anatomy physiology and health question 26 what is the function of the circulatory system a to transport oxygen and nutrients to cells and remove waste products B to control movement and support the body C to exchange gases with the environment D to provide structure and protection for the body the correct answer is a to transport oxygen and nutrients to cells and remove waste products to pass the GED you'll need an idea of what the organ systems are the circulatory system is responsible for transporting oxygen and nutrients to cells and removing waste products such as carbon dioxide from the body other organ systems are respiratory system this system is responsible for bringing oxygen into the body and removing carbon dioxide digestive system the digestive system processes food and extracts nutrients from it nervous system this system controls and coordinates the body's responses to internal and external stimuli endocrine system the endocrine system produces and releases hormones that regulate various bodily functions muscular system this system allows the body to move and maintain posture skeletal system the skeletal system provides support for the body and protects internal organs integumentary system this system is responsible for protecting the body from external damage and regulating temperature question 27 what is the role of the respiratory system a to break down food and absorb nutrients B to eliminate waste products from the body C to transport oxygen and nutrients to cells D to exchange gases with the environment the correct answer is D to exchange gases with the environment the respiratory system is responsible for exchanging gases with the environment specifically oxygen and carbon dioxide oxygen is brought into the body and carbon dioxide is removed question 28 what is the difference between voluntary and involuntary muscles a voluntary muscles are only found in the arms and legs while involuntary muscles are found in the internal organs B voluntary muscles are controlled consciously while involuntary muscles are controlled automatically by the nervous system C voluntary muscles are found in the heart while involuntary muscles are found in the limbs D voluntary muscles are responsible for maintaining posture while involuntary muscles are responsible for movement the correct answer is B voluntary muscles are controlled consciously while involuntary muscles are controlled automatically by the nervous system voluntary muscles are under conscious control meaning that they are controlled by the brain and can be moved at well involuntary muscles on the other hand are controlled automatically by the nervous system and cannot be consciously controlled question 29 what is the function of the immune system a to transport oxygen and nutrients to cells and remove waste products B to control movement and support the body C to exchange gases with the environment D to defend the body against pathogens in foreign substances the correct answer is D to defend the body against pathogens and foreign substances the immune system is responsible for defending the body against pathogens such as viruses and bacteria and foreign substances such as toxins and allergens question 30 what is the difference between a virus and a bacterium a viruses are larger than bacteria B bacteria can reproduce outside of a host organism while viruses cannot C bacteria are the cause of all infectious diseases while viruses are not harmful to humans D viruses are only found in animals while bacteria are found in all living organ organisms the correct answer is B bacteria can reproduce outside of a host organism while viruses cannot bacteria are single celled microorganisms that can reproduce independently while viruses are not alive and must infect living cells to reproduce lesson eight matter properties States and phase changes question 31 the information below describes the properties of two substances which substance is denser substance a is 20 G and has a volume of 10 cm cubed substance B is 15 G and has a volume of 5 cm cubed a substance a b substance b c both substances have the same density D cannot be determined from the information given density is calculated by dividing the mass of a substance by its volume therefore the density of substance a is 20 G / 10 cm cubed this is equal to 2 G per cm cubed the density of substance B is 15 G / 5 cm cubed this will be equal to 3 G per cm cubed since B is greater than a it means substance B is dense than substance a so the correct answer is B question 32 what is the phase change that occurs when a solid becomes a gas a condensation B melting C freezing D sublimation the correct answer is D sublimation sublimation is the phase change that occurs when a solid changes directly to a gas without first becoming a liquid examples of substances that undergo sublimation include dry ice that is solid carbon dioxide and moth balls that is solid nylene let's look at what the other things mean it's important to know them condensation is the phase change in which a gas turns into a liquid melting is the phase change in which a solid turns into a liquid freezing is the phase change in which a liquid turns into a solid question 33 which of the following is an example of a physical property of matter a flammability B reactivity C density D pH the correct answer is C density physical properties of matter are characteristics that can be observed or measured without changing the composition of the substance examples of physical properties include density color texture and melting point flammability reactivity and pH are examples of chemical properties which describe how a substance interacts with other substances to form new substances thanks for joining us for part three of our GED science course from Ultimate ged.com part three and part four will have most of our GED science calculations let's Dive Right In lesson 9 atomic theory structure and the periodic table the table in the corresponding graph displays various properties of selected elements the table lists the atomic number and number of protons of each element while the graph displays the electro negativity values of the elements use these to answer the following questions question 34 which of the statements below is true a the atomic number is equal to the number of electrons in the atom B the the atomic number is equal to the number of neutrons in the atom C the atomic number is equal to the sum of the number of protons and neutrons in the atom D the atomic number is equal to the number of protons in the atom some GED science questions requires the use of multiple data points like two graphs or a graph and a table combined to get your answers that's what we are looking at here the correct answer is D the atomic number is equal to the number of protons in the atom this first question is pretty straightforward we can see from the table that the atomic number is always the same as the number of protons question 35 how does the electr negativity Trend vary among the elements carbon nitrogen oxygen and Florine a electr negativity decreases from car carbon to Florine B electro negativity increases from carbon to Florine C electro negativity remains constant among carbon nitrogen oxygen and Florine D there is no clear Trend in electro negativity among carbon nitrogen oxygen and Florine the correct answer is B electro negativity increases from carbon to Florine this is pretty easy we can see from the graph that the electro negativity values are increasing on this graph As you move from carbon to FL question 36 which of the following is true about elements in the same group on the periodic table a they have similar atomic masses B they have similar Electro negativities C they have the same number of electrons D they have similar chemical properties the correct answer is D they have similar chemical properties elements in the same group on the periodic table have the same number of veence electrons which determines their chemical properties veence electrons are simply the electrons in the outermost shell or energy level of an atom for example elements in group one such as lithium sodium and potassium all have one veence electron and are highly reactive with other elements from these images you can see that although these elements have different number of electrons they all have just one electron on the last shell please check out ultimate ged.com for more lessons on the atomic structure question 37 which of the following subatomic particles are typically found in the nucleus of an atom proton neutron electron the correct answer is proton and neutron in the previous question we used a simple diagram to represent an atom because we only cared about the shells this diagram here is a better representation of an atom both protons and neutrons are typically found in the nucleus of an atom protons have a positive charge while neutrons have no charge they are neutral electrons on the other hand are not found in the nucleus but orbit around it in energy levels or shells lesson 10 chemical bonding reactions and stoic geometry question 38 what is the balanced chemical equation for the reaction between hydrogen gas and oxygen gas to form water a 2 H2 reacts with O2 to get H2O B H2O breaks down to 2 H2 and O2 c 2 H2 reacts with O2 to give 2 H2O d 2 H2O breaks down to H2 and O2 the correct answer is C two molecules of hydrogen gas react with one molecule of oxygen gas to produce two molecules of water balancing equations is one of the most important things on the GED our work here is to make sure that there are equal numbers of atoms of each element on both sides of the equation on the left side there are four atoms of hydrogen that is the two * this two for the oxygen there are two atoms on the right side please note that these two affect both the hydrogen and oxygen so there are four atoms of hydrogen which is this two * this two and there are two atoms of oxygen because of this two so we can see that there are the same amount of hydrogen and oxygen on both sides of the equation so it is balanced please go to Ultimate ged.com and try on your hands on more examples this requires practicing question 39 what is the coefficient for the oxygen gas in the balanced chemical equation for the combustion of propane to form carbon dioxide and water a 2 B 3 C 4 d 5 the correct answer is D5 the work here is to make sure that the number of atoms of oxygen are the same on both sides of the equation we need to find all the oxygen on the right side and make sure that there are the same number of molecules on the left side on the right side oxygen is found in the carbon dioxide and the water for the carbon dioxide we have 3 * 2 remember we said that this three multiplies both the carbon and the oxygen this will give us six atoms of oxygen for the water we have 4 * 1 this will give us four again remember the preceding four multiplies both the hydrogen and the oxygen the total number of oxygen atoms is therefore 10 to balance it out we need 10 atoms of oxygen on the left side so we can put five molecules here the five will multiply the two to get 10 now the molecules of oxygen is the same on both sides so it is balanced please please it's important you practice more examples on this lesson 11 thermodynamics and heat transfer Carla and Mark are chemistry students who are conducting an experiment to study the effects of heat transfer in chemical reactions they mix two substances together in a beaker and notice that the temperature of the mixture increases Carla explains that this reaction is exothermic because it releases heat into the surroundings Mark is curious and asks if there are any reactions that absorb heat Carla nods and suggests they mix another set of substances to demonstrate an endothermic reaction they mix the second set of substances together and notice that the temperature of the mixture decreases confirming that it is endothermic question 40 how can you tell if a reaction is exothermic or endothermic a by measuring the temperature change of the reaction B B by measuring the weight of the reactants and products C by measuring the volume of the reactants and products d by measuring the color change of the reaction the correct answer is a by measuring the temperature change of the reaction in the passage Carla and Mark were able to determine whether a reaction was exothermic or endothermic by observing the temperature change of the mixture this is part four of our GED science course please it's important you watch the entire playlist of four videos we cover all the major topics you need to pass the GED science don't forget to check out ultimate ged.com for more let's dive in mechanics fluid dynamics and properties of gas Mike releases a ball from rest at the top of a ramp the ball rolls down the ramp due to gravity and its kinetic energy increases as it accelerates by the time the ball reaches the bottom of the ramp it has gained 5 jewles of kinetic energy the relationship between gravitational potential energy and kinetic energy for an object moving solely under the influence of gravity is potential energy lost equals kinetic energy gained question 41 if the ball started from a height h m and its weight is 10 Newtons how high is the ramp a 0.25 m b 0.5 m c 1.0 m d 2.0 M the correct answer is B 0.5 M for questions in this section all the formulas will be given to you but you'll have to understand the relationship of the information in order to solve the potential energy due to gravity is given by the formula weight time height so to find the height we need to know the weight and the potential energy the weight has been given to us as 10 Newtons the potential energy has not been given to us however the kinetic energy gained has been given to us as 5 jewles we know that the potential energy lost is the same as the kinetic energy gained so the potential energy will also be 5 Jew we have 5 = 10 * h we can now solve for H divide both sides by 10 the 10 will cancel out 5 / 10 is 0.5 so the height is 0.5 M question 42 a container holds a fixed amount of an ideal gas if the pressure of the gas in the container is doubled while keeping the volume and number of moles constant what happens to the temperature of the gas the ideal gas law is PV equals nrt where p is pressure V is volume n is the number of moles R is the gas constant and T is temperature a it Remains the Same B it is Haled C it doubles D it quadruples the correct answer is C it doubles please do not overthink on GED calculation questions or question like this they are usually designed to test your ability to recognize patterns and relationships and accurately interpret and use formulas for this question all we have to keep in mind is that it is an equation to keep it equal whatever you do to one side must be done to the other side we are told that the pressure is doubled so we can multiply pressure by two to balance the equation we have to multiply something on the right side by two we are told that the volume and number of moles are constant so we cannot do anything to it R is also a constant it is the gas constant to balance it we can only multiply the temperature by two this means that the temperature doubles lesson 13 waves electricity and magnetism question 43 a sound wve has a frequency of 500 Herz and a wavelength of 0.68 M what is the speed of sound in m/s a 340 m/s B 500 m/s C 680 m/s D 850 m/s the correct answer is a 340 m/s the speed of sound in air can be calculated Cal ated using the formula v = f * Lambda where V is the speed f is the frequency and Lambda is the wavelength this formula as always will be given to you on the test your work is just applying it we have been given the frequency as 500 and the wavelength as 0.68 plugging in the values we get V = 500 * 0.68 this will give us 300 40 m/s question 4 to4 a circuit with a resistance of 10 ohm is connected to a 12vt power source what is the current flowing through the circuit a 0.12 amp B 1.2 amp C 12 amp D 120 amp the correct answer is B 1.2 amp this is another formula work we will be using om's law V equals I where V is voltage I is current and R is resistance this formula will be given to you we have been given the voltage as 12 we've also been given the resistance as 10 our work is to solve for I divide both sides by the 10 the 10 will cancel out 12 / 10 is 1.2 therefore or the current flowing through the circuit is 1.2 amp lesson 14 Earth and space science in the desert of the American southwest a stunning geological feature draws scientists and tourists alike this feature known as the Red Rock Canyon showcases layers of sedimentary rock predominantly Sandstone that have been sculpted by wind and water over millions of years the Striking red color of the rock is due to the presence of iron oxide or rust which has Stained the Sandstone over time geologists are particularly interested in the Canyon's rock formations which provide a window into Earth's geological history fossilized remains of ancient plants and animals have been discovered Within These layers offering clues about the Region's past environments the Canyon's unique topography also reveals the powerful forces of erosion which have shaped the landscape into its current form question 45 what causes the red color of the rocks in Red Rock Canyon a high quartz content B presence of iron oxide C erosion by water D volcanic activity the correct answer is B the presence of iron oxide from the passage we know that the strik red color of the rock is due to the presence of iron oxide or rust which has Stained the Sandstone over time question 46 which type of rock is formed by the cooling and solidifying of magma or lava a sedimentary b ous c metamorphic D Limestone the correct answer is B Ignus rocks ous rocks are formed from the solidification and cooling of magma or lava common examples are granite and basalt it's important you know the other types of rocks sedimentary rocks these are formed from the accumulation or deposition of mineral and organic particles often in water bodies like rivers lakes and oceans an example is sandstone and Shale metamorphic rocks these rocks are formed from the transformation of existing rock types in a process known as metamorphism which means change in form examples include slate formed from Shale and marble formed from Limestone Limestone this is actually a specific type of rock typically a sedimentary rock rather than a category of rock limestone is primarily composed of the mineral calite calcium carbonate and forms largely in aquatic environments from the accumulation of shells Coral algae and other organic materials question 47 which of the following planets is known as the red planet due to its reddish appearance a Venus B Mercury C Mars D Jupiter the correct answer is C Mars Mars is commonly referred to as the red planet because of its distinct reddish hue this coloration is due to the presence of iron oxide or rust on its surface it's important you know some basic information about planets like what planet has a ring what planets are closet to Earth lesson 15 environmental science and sustainability question 48 what is the primary cause of the current Trend in global warming and climate change a decrease in volcanic activity B increase in solar radiation C decrease in ocean currents D increase in greenhouse gas emissions the correct answer is D increase in greenhouse gas emissions these gases which include carbon dioxide methane and nitrous oxide trap heat in the Earth's atmosphere leading to a warming effect known as the greenhouse effect question 49 which of the following is a consequence of climate change that affects Coastal communities a increased soil fertility B decreased hurricane activity C rising sea levels D decreased rainfall in desert the correct answer is C rising sea levels as global temperatures rise polar ice caps and Glaciers melt contributing to higher sea levels Additionally the warming of the ocean leads to thermal expansion of water further elevating sea levels this results in increased Coastal erosion flooding and can even lead to the displacement of communities it also threatens important ecosystems such as mangroves and coral reefs question 50 sustainable development primarily aims to a maximize short-term economic growth B use resources to meet human needs while preserving the environment for future Generations C Focus solely on conservation of Natural Resources D promote industrialization at any cost the correct answer is B use resources to meet human needs while preserving the environment for future Generations the goal is to use resources in a way that meets the needs of the present without compromising the ability of future generations to meet their own needs get more watch the GED science playlist GED math playlist and get the full GED math course