8th Grade Practice Exam

Front

What is the Law of Conservation of Energy?

Back

The Law of Conservation of Energy states that energy cannot be created or destroyed, only transformed from one form to another.

Front

What is a mixture?

Back

A mixture is a combination of two or more substances where each substance retains its own properties and can be physically separated.

Front

What is thermal energy?

Back

Thermal energy is the energy that comes from the temperature of matter. It is the total kinetic energy of the particles in a substance.

Front

How is heat transferred?

Back

Heat can be transferred through conduction (direct contact), convection (movement of fluids), and radiation (transfer through electromagnetic waves).

Front

What is the difference between a homogeneous mixture and a heterogeneous mixture?

Back

A homogeneous mixture has a uniform composition throughout (e.g., milk), while a heterogeneous mixture has a non-uniform composition (e.g., pizza).

Front

What happens during a chemical reaction?

Back

During a chemical reaction, substances (reactants) are transformed into new substances (products) through the breaking and forming of chemical bonds.

Front

What is an example of energy transformation?

Back

An example of energy transformation is when striking a match, where mechanical energy is converted into heat energy.

Front

What is a solution?

Back

A solution is a homogeneous mixture where one substance (solute) is dissolved in another (solvent), such as salt in water.

Front

What is a suspension?

Back

A suspension is a heterogeneous mixture where solid particles are dispersed in a liquid but can settle over time, like muddy water.

Front

What is the difference between a compound and a mixture?

Back

A compound is a substance formed when two or more elements chemically bond together, while a mixture is a physical combination of substances.