what's going on besties today we're going to be covering the te's version 7 science portion more specifically chemistry and we're going to be talking about physical properties and changes of matter let's get started so it's important to note that everything around you is made up of matter it can exist in different states it could be solid it could be liquid or it could be a gas these states can change between each other demonstrated by water water vapor represents a gaseous State while liquid water and ice cubes exemplify a liquid and solid state respectfully let's now discuss Mass which refers to the amount of matter contained in an object for example a basketball is larger than a tennis ball so it typically has more mass we measure the mass of objects in grams or even kilogram using instruments like balances and scales volume is the amount of space an object occupies we typically measure volume in either liters or even milliliters graduated cylinders and measuring beakers are common tools for measuring volume of liquids and then lastly we have density and this is defined as the relationship between an object's mass and its volume for example let's consider a block of lead and a block of wood that are roughly about the same size meaning that they have similar volumes however that lead is going to be significantly heavier indicating a greater mass which results in differing densities between the two to to calculate the object's density you're going to divide the mass by its volume using the formula density which is density equals mass / by volume if we examine various examples of water we can find that nearly everything can be classified in one of three states solids liquids and gas these categories are referred to as phases of matter or states of matter while there are other less common phases like we see with plasma we're going to focus on the main three for now you're likely familiar with these phases from everyday experiences but let's explore them from a more scientific or technical perspective like you're going to be tested on the te's we'll begin with solids here we have some examples of solids we have a block of ice we have a diamond and we have a piece of wood most of us have an intuitive understanding of what a solid is but how do we Define it scientifically a solid is defined as having a definite shape and a definite volume definite means they are fixed and unchangeable under normal conditions for instance unless subjected to force or damage a solid like a diamond is going to retain its shape and speaking of volume which is the amount of space an object occupies a solid has a fixed volume as well take a cube with dimensions of 1 cm on each side its volume would be 1 cubic cm whether you move this cube roll it around it doesn't matter it's volume is going to remain unchanged it is definite another key characteristic of solids is that they are incompressible meaning that we cannot compress them this means that no matter how much force we apply that solid is never going to compress into a smaller volume here are the fundamental characteristics that define a solid so we're going to dive a little bit closer into the microscopic view of a solid to better understand its structure if we were to zoom in on this solid a bit million times we're going to see that it consists of tiny little particles which represent small circles or spheres as we observe these particles a few things are going to become very clear firstly They are packed tightly together although we can't illustrate it here these particles are not static they're constantly vibrating inside of our solid quivering back and forth however these particles are anchored to one spot they're not going to wander to new locations they're going to remain fixed in the location they are always vibrating and always wiggling this microscopic Behavior directly influences the microscopic characteristics of solids for example solids have a definite shape like we talked about before and that's because these particles are fixed in their specific locations to alter the shape of a solid such as a cube the particles composing it would need to relocate so an example of this could be a brick building for example the bricks much like the particles in our solid don't easily sh shift to form a new shape because they're fixed into place and lastly solids are incompressible because there is minimal space in between these particles to make it possible for them to become packed any more tightly close together regardless of how much force is applied so here's everything you're going to need to know about solids as we work through our examples we're going to continue to build upon our knowledge of different phases of matter let's now discuss liquids so what characterizes a liquid technically a liquid has an indefinite shape but it has a definite volume let's unpack exactly what that means a liquid freely flows and conforms to the shape of its container such as a bottle that is what is demonstrated by this property every time you transfer this liquid to a new container whether it's a glass a bottle or even a beaker it's going to assume that different kind of shape this is why we describ the liquid as having an indefinite shape however Aid liquid maintains a definite volume for example regardless of the container's shape if you measure the liquid the volume remains consistent say I have 1 liter in this bottle and I dump that one liter into this bottle it doesn't matter whether the bottle shapes are different that liquid volume is going to remain the same additionally liquids are incompressible which may be surprising for a lot of you for instance if we place liquid inside of a syringe and we seal it on the top no matter how much we try to compress it we're not able to push that plunger up or down because the liquid simply is so compact it's incompressible therefore you cannot squeeze a liquid into a smaller volume so let's take a closer look at what the particles of liquid look like unlike the particles that we see in solid which are tightly packed together the particles in liquid are close together but they exhibit much greater movement in liquid particles are not fixed but they move more freely around each other they swim they're going to wiggle a little bit past each other this is actually observed here in our diagram this mobility of particles is key to understanding why liquid has an indefinite shape because these particles can move more freely they can adapt to new locations easily this is what allows liquid to pour and take on shapes of their containers they simply tumble around each other and settle into their new configuration however despite this movement liquids is still incompressible like solids while the particles in liquid have slightly more freedom compared to their solids there still isn't a significant amount of space between them in order to allow for that compression like we saw with the syringe they can't be squished any closer together which maintains their compressibility now we have everything we need to know for liquids now let's discuss our final phase of matter gas gases might seem a bit peculiar because most of them are invisible like air and only a few gases are actually visible to the human eye sometimes people might think that gases actually aren't matter but in contrast they actually are regarding their specific characteristics gases have both an indefinite shape and an indefinite volume like liquids gases shapes change to fit whatever container they're in which is why their shapes are considered indefinite however gas volumes also change for instance the gas currently occupies this bottle but if I was to remove the top from this bottle and allow some of the gas out that gas is going to expand and fill a larger volume gases can expand or contract to fill any available space making their volumes indefinite as well unlike their solid and liquid counterparts gases are compressable if we were to take that same syringe from before and get all of the water out of it and fill it up with just gas I'm going to put the plunger back on top we're going to see that as I push the plunger down look at that I'm able to compress the gas inside of this syringe this compressibility is a distinctive property to gases differentiating them from all other states of matter so let's take an even closer look at gas zooming in we can see that particles are really spaced out and they're constantly in Rapid motion zipping around at high speed gases like liquids have an indefinite shape because our particles are free to move around to any new location they also possess an indefinite volume meaning that they can expand and they can contract depending on the available space this ability to change volume is due to the particles being really far apart from one another and them being in constant motion when given more space the particles are going to spread farther apart however if we compress that space and give them a smaller space they're going to ultimately draw closer together this explains why solids and liquids have a definite volume their particles are packed closely together and they don't separate or spread apart significantly like we see with gas this brings us to the concept of compressibility when it comes to gases gases are compressible because our particles are so spaced out leaving a lot of room in between them like we saw with our syringe example because there's so much space in between our gas here in the syringe we are able to compress them into a smaller volume and there you have it here is our completed breakdown of all of the different states of matter that you're going to need to know for the aits so let's explore how temperature and pressure is going to influence changes of our states of matter using water as our example to begin let's consider a beaker containing a big block of ice attached to a thermometer as we start heating up that ice increasing our temperature the temperature recorded by the thermometer is going to increase until it reaches a critical point at this this stage our ice is going to start transforming into water on a microscopic level imagine numerous little ice particles tightly packed together in their solid form each of them are vibrating in place as heat is applied we're going to see an increase in kinetic energy causing them to vibrate even faster continued heat is going to allow these particles to overcome the force holding them together enabling to start to move more freely and transition into a liquid state what's really interesting is that during the transition from Ice to water the temperature remains a constant 0° C this temperature is known as our melting point for ice this melting point reflects the minimal amount of energy required to weaken and break apart those intermolecular forces binding the particles together once all of our ice has melted the temperature of the water is going to remain at 0° C until the ice has completely transitioned into water any addition addal heat supplied during this phase is used to break the remaining intermolecular bonds after all the ice has melted and if the heating continues the water of the temperature begins to rise again when the temperature reaches 100° C the water starts to boil boiling is a phenomenon that occurs throughout the liquid signifying the transition from liquid into gas once it reaches the boiling point at this stage the particles already moving freely gain sufficient kinetic energy to overcome their intermolecular bonds and enter into a more gaseous State completely next up let's consider how pressure affects the state of matter using gas in a bottle as an example if we compress the gas by pushing down our plunger reducing the volume the particles are going to be forced to move closer together if the temperature within the system is always kept low The increased pressure and reduced volume causes those Gas part particles to attract to each other strongly enough that it's going to start to transition into a liquid this process demonstrates how increasing pressure particularly in combination with lower temperatures can liquefy gases in addition to knowing that matter exists in these three states solid liquids and gases you also need to know the six Transformations that can take place between them let's discuss each one of these in detail so starting with melting melting is the process where a solid becomes a liquid when it absorbs heat so an example of this is like we talked about before with ice melting into water this is the most common example as the ice absorbs heat from its surroundings its molecules increase its kinetic energy weakening those intermolecular forces that have kept them fixed in place allowing them to move more freely and transition into a liquid state freezing on the other hand is defined as the process where liquid turns into a solid state this occurs when the the liquid loses heat causing those molecules to slow down and rearrange into a fixed solid structure a common example of this is when water freezes into ice when the temperature of water drops below 0° C or 32° fit the movement of water molecules slows down sufficiently so that they can crystallize into ice next up we have condensation and condensation is the transformation of a gas into a liquid this happens when a vapor loses energy and its molecules slow down enough to stick together forming a liquid a common example of this is when water vapor condenses on a cold glass that cold surface is going to cool the water vapor that's found in the air reducing its energy and converting it back into liquid droplets and then we have evaporation so evaporation is the process of a liquid turning into a vapor or a gas at a temperature below its boiling point it typically occurs at the surface of a liquid so an example of this could be water evaporating on a pond even on a cool day water molecules at the surface can gain enough energy from the Sun to escape into the air as vapor and our last two examples is sublimation and deposition so when we're talking about sublimation we're talking about the direct transition from a solid into a gas bypassing the liquid state altogether this occurs under specific conditions when it comes to temperature and and pressure a common example of seeing this is dry ice which is solid carbon dioxide ultimately sublimating at room temperature dry ice turns directly into carbon dioxide gas rather than first melting into a liquid and then lastly we have deposition which is the direct transition from a gas into a solid state completely again skipping that liquid phase this occurs when those gas molecules lose energy very very quickly so a example of this could be frost forming on your window so on a cold winter day that water vapor that's going to be found in the air can directly pause it onto the cold window pane as ice without ever having to become a liquid first so let's do some practice questions what is the process called when a solid turns directly into a gas is it condensation deposition sublimation or evaporation and the correct answer is C sublimation remember SU infation is the process where a solid transitions directly into a gas without passing through that liquid phase this is observed with things like dry ice like we talked about before where it turns directly into carbon dioxide gas when it's exposed to room air temperatures what state of matter has a definite volume but not a definite shape is it solid liquid gas or plasma and the correct answer is B liquid remember liquid has a definite volum volume meaning that they occupy a set amount of space but they do not have a definite shape instead they take the shape of the container that they're in which of the following is not a characteristic of a solid is it a a fixed volume b a fixed shape c the ability to flow or D not being compressible and the correct answer is C its ability to flow remember solids have a fixed shape and they have a fixed volume but unlike liquid andas gases they don't flow they just kind of vibrate in place in their fixed positions what is the term for the temperature at which a liquid turns into a gas is it the freezing point boiling point melting point or sublimation point and the correct answer is B the boiling point the boiling point is the temperature at which liquid changes into a gas occurring throughout the bulk of the liquid not just on the surface as we see with evaporation I hope that this video was helpful understanding everything you need to know when it comes to physical properties and changes of matter as always if you have any questions make sure that you leave them down below I love answering your questions head over to nurse Chun store.com where there's a ton of additional resources to help you Ace those aits exams and as always I'm going to catch you in the next video bye