Chemical Reactions and Changes

Front

What is a chemical reaction?

Back

A process where substances (reactants) change into new substances (products) with different properties.

Front

What is a physical change?

Back

A change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What is a chemical change?

Back

A change that results in the formation of new chemical substances.

Front

Is dissolving sugar in water a chemical reaction?

Back

No, it is a physical change because the sugar can be recovered.

Front

What happens to the mass of reactants in a chemical reaction?

Back

The total mass of the reactants is equal to the total mass of the products.

Front

What is an example of a chemical change?

Back

Burning wood, which produces ash and smoke.

Front

What is an example of a physical change?

Back

Melting ice, which turns into water but remains H2O.

Front

What evidence indicates a chemical change has occurred?

Back

Color change, gas production, temperature change, or formation of a precipitate.

Front

What is the law of conservation of mass?

Back

Mass is neither created nor destroyed in a chemical reaction.

Front

What happens to sugar when it is heated?

Back

It undergoes a chemical change and can turn black due to caramelization.