Unit test review

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Example: Ice melting into water.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Example: Production of gas when vinegar reacts with baking soda.

Front

What are reactants in a chemical equation?

Back

Reactants are the starting substances in a chemical reaction that undergo change to form products. Example: In the equation N2 + H2 -> NH3, N2 and H2 are the reactants.

Front

What does it mean for a chemical equation to be balanced?

Back

A balanced chemical equation has the same number of each type of atom on both sides of the equation, indicating that mass is conserved during the reaction.

Front

What is decomposition in chemistry?

Back

Decomposition is a type of chemical reaction where a single compound breaks down into two or more simpler substances. Example: Breaking down water into hydrogen and oxygen.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form or appearance of a substance without changing its chemical composition, while a chemical change results in the formation of new substances.

Front

What is an example of a chemical change?

Back

An example of a chemical change is rust forming on iron, which involves a reaction with oxygen.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; it is conserved.

Front

What is a balanced chemical equation?

Back

A balanced chemical equation has equal numbers of each type of atom on both sides, ensuring that mass is conserved.

Front

What indicates a chemical change has occurred?

Back

Indicators of a chemical change include color change, temperature change, production of gas, and formation of a precipitate.