7th Grade Fall Semester Exam

Front

What is a precipitate?

Back

A precipitate is a solid that forms and settles out of a liquid mixture as a result of a chemical reaction.

Front

What happens when two solutions are mixed and a precipitate forms?

Back

A chemical change occurs, resulting in a new substance.

Front

What is the effect of temperature on the solubility of solids in water?

Back

Using hotter water generally increases the solubility of solids, while colder water decreases it.

Front

How does surface area affect the rate of dissolution of a solid in a liquid?

Back

A greater surface area allows for faster dissolution because more particles are exposed to the solvent.

Front

What is Newton's first law of motion?

Back

An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an unbalanced force.

Front

What is conduction?

Back

Conduction is the transfer of thermal energy through direct contact between materials.

Front

What is convection?

Back

Convection is the transfer of thermal energy through the movement of fluids (liquids or gases).

Front

What is radiation?

Back

Radiation is the transfer of energy through electromagnetic waves, which can occur in a vacuum.

Front

What is an example of a physical change?

Back

Dissolving sugar in water is a physical change because the sugar can be recovered.

Front

What is an example of a chemical change?

Back

Burning wood is a chemical change because it produces new substances (ash, smoke, gases).