Energy and Matter Changes

Front

What is a heterogeneous mixture?

Back

A heterogeneous mixture is a type of mixture where the components are not uniformly distributed, and different parts can be seen and separated easily. Example: Salad.

Front

What is a homogeneous mixture?

Back

A homogeneous mixture is a mixture in which the components are evenly distributed and cannot be easily distinguished. Example: Saltwater.

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. Example: Ice melting.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Example: Rust forming on iron.

Front

Can matter be created or destroyed?

Back

No, matter cannot be created or destroyed; it can only change forms, according to the law of conservation of mass.

Front

What is an endothermic reaction?

Back

An endothermic reaction is a chemical reaction that absorbs heat from its surroundings. Example: Dissolving ammonium chloride in water.

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases heat to its surroundings. Example: Combustion of wood.

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; it remains constant.

Front

What happens to energy during a physical change?

Back

During a physical change, energy may be absorbed or released, but the substance's chemical identity remains the same.

Front

What happens to energy during a chemical change?

Back

During a chemical change, energy is either absorbed or released, and new substances are formed.