Define element.
A substance that cannot be broken down into simpler substances.
What is a compound?
A substance formed when two or more elements chemically bond together.
Fill in the blank: A molecule is the smallest unit of a _______.
Compound
True or false: Molecules can consist of the same or different elements.
TRUE
What is the rate of reaction?
The speed at which reactants are converted into products in a chemical reaction.
Define independent variable.
The variable that is changed or controlled in a scientific experiment.
What is a dependent variable?
The variable that is measured or tested in an experiment.
Fill in the blank: Controls are factors that are kept _______ in an experiment.
Constant
True or false: Controls help ensure that the results are valid.
TRUE
What is the role of catalysts in reactions?
They speed up the rate of reaction without being consumed.
Define reactants.
Substances that undergo a chemical change in a reaction.
What is the activation energy?
The minimum energy required for a chemical reaction to occur.
Fill in the blank: The law of conservation of mass states that mass is _______ in a chemical reaction.
Neither created nor destroyed
True or false: Increasing temperature generally increases the rate of reaction.
TRUE
What is concentration in relation to reactions?
The amount of a substance in a given volume, affecting reaction rates.
Define product.
The substances formed as a result of a chemical reaction.
What does collision theory state?
For a reaction to occur, reactant particles must collide with sufficient energy.
Fill in the blank: Surface area affects the rate of reaction by increasing _______.
Collisions
True or false: A higher pressure can increase the rate of reaction for gases.
TRUE
What is the effect of pH on reaction rates?
It can alter the activity of enzymes and affect reaction speed.
