Chemical Reactions vs Physical Changes

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.

Front

What is a chemical change?

Back

A chemical change occurs when substances react with each other to form new substances with different properties.

Front

Is freezing water a physical or chemical change?

Back

Physical change.

Front

Is burning wood a physical or chemical change?

Back

Chemical change.

Front

What is an example of a physical change?

Back

Melting ice, dissolving sugar in water.

Front

What is an example of a chemical change?

Back

Rusting of iron, baking a cake.

Front

What happens to the molecules during a physical change?

Back

The molecules may change their arrangement or state, but their chemical structure remains the same.

Front

What happens to the molecules during a chemical change?

Back

The molecules react and rearrange to form new substances with different chemical structures.

Front

What is a sign that a chemical change has occurred?

Back

Signs include color change, temperature change, gas production (bubbles), or the formation of a precipitate.

Front

What is the law of conservation of mass?

Back

The law states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.