Semeter 1 review CHEMISTRY

Front

What is density?

Back

Density is the mass of a substance divided by its volume, often expressed in grams per cubic centimeter (g/cm³).

Front

True or False: The density of a specific type of material never changes.

Back

True

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

Why is the change of shape in clay considered a physical change?

Back

Because the clay can be reshaped back to its original form without any chemical alteration.

Front

What is a chemical change?

Back

A chemical change occurs when a substance transforms into a different substance with different properties, such as burning wood producing ashes.

Front

True or False: Experiments should be repeated to verify results.

Back

True

Front

What is a solution?

Back

A solution is a homogeneous mixture formed when a solid is dissolved in a liquid.

Front

What is the difference between an endothermic and exothermic reaction?

Back

An endothermic reaction absorbs heat, while an exothermic reaction releases heat.

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.

Front

What is an example of a physical change?

Back

Melting ice is an example of a physical change.