Chemistry and Experimental Design Lecture Notes

Part 1: Chemistry Basics

Key Concepts of Chemical Reactions

• Products of Chemical Reactions:
  • Chemical reactions result in the formation of products such as molecules and atoms.
• Rearrangement of Atoms:
  • Atoms rearrange by forming and breaking bonds with other atoms, leading to the creation of new substances.

Important Vocabulary

• Atom: The smallest unit of matter, forming the fundamental components of all substances.
• Chemical Reaction: A process where atoms rearrange, leading to new substances.
• Model: A representation or tool that helps in understanding complex concepts.
• Product: The substance formed as a result of a chemical reaction.
• Property (Chemical, Physical): Observable characteristics, such as color, smell, and boiling point.
• Reactant: The initial substances involved in a chemical reaction.
• Rearrange: Changing the order or position of components.
• Scale: Refers to the relative size of things.
• Substance: Consists of the same type of atoms or groups of atoms.

Additional Chemistry Terms

• Boiling: Transition of a liquid into a gas.
• Chemical Change: Formation of a new substance via a chemical reaction.
• Chemical Equation: Representation of a chemical reaction showing the atoms involved.
• Compound: A chemical formula consisting of two or more types of atoms.
• Dissolving: Mixing a substance with a liquid to form a solution.
• Element: A pure substance made of one type of atom, listed on the periodic table.
• Freezing: Transition of a liquid to a solid.
• Heterogeneous Mixture: A mixture where individual components are not evenly mixed and are distinguishable.
• Homogeneous Mixture: A mixture with evenly mixed individual substances.
• Mass: A measure of the amount of matter in an object.
• Matter: Occupies space and has mass; composes all objects.
• Melting: Transition of a solid to a liquid.
• Phase Change: The transition between states of matter.
• Physical Change: Matter changes form without a chemical reaction, with no new substances formed.
• Thermal Energy: Heat energy.

Part 2: Experimental Design

4Q Strategy for Experimentation

• Available Materials: Identify and utilize easily accessible materials for experiments.
• Behavior of Materials: Understand how materials act under certain conditions.
• Modification of Conditions: Alter materials to study changes in behavior.
• Measurement of Responses: Develop methods to measure or describe outcomes from changes.

Vocabulary for Experimental Design

• Constants: Variables that remain unchanged to ensure a valid experiment.
• Dependent Variable (DV): The observed effect resulting from the independent variable.
• Experiment: A scientific test of a hypothesis to determine if the independent variable affects the dependent variable.
• Independent Variable (IV): The factor manipulated in an experiment to study its effects.
• Hypothesis: A testable idea often structured as "If (IV), then (DV)."
• Observation: Gathering data through sensory experiences (e.g., texture, smell, color).
• Repeated Trials: Conduct the same experiment multiple times for accuracy.
• Validity: The degree to which an experiment measures what it intends to measure; having only one IV increases validity.
• Variable: Any factor that can vary or change during an experiment.

Practical Applications

• 4Q and EDD (Experimental Design Diagram): Tools to design, conduct, and evaluate scientific experiments effectively.