Physical and chemical changes

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction; it can only change forms.

Front

What happens to hot air compared to cooler air?

Back

Hot air rises because it is less dense than cooler air.

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases heat, causing the temperature of the surroundings to increase.

Front

What is evidence of a chemical change?

Back

Evidence of a chemical change can include gas production, color change, temperature change, or odor change.

Front

What is density?

Back

Density is the mass of a substance divided by its volume, often described as how heavy something is for its size.

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 a substance transforms into a different substance with different properties.

Front

What is an example of a physical change?

Back

Melting ice is an example of a physical change; the ice changes from solid to liquid but remains water.

Front

What is an example of a chemical change?

Back

Burning wood is an example of a chemical change; it transforms into ash and gases.

Front

What is an insulator?

Back

An insulator is a material that does not conduct heat or electricity well.