Chemistry Test Review

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Examples include hydrogen (H) and oxygen (O).

Front

What are atoms?

Back

Atoms are really small particles that can join to make up molecules.

Front

What does it mean if an object has low density?

Back

An object has low density if it floats in a fluid, indicating that it is less dense than the fluid. For example, a ping pong ball floats on water.

Front

What is a pure substance?

Back

A pure substance is made up of one type of material throughout, such as distilled water or pure gold.

Front

What is evidence of a chemical reaction?

Back

Evidence of a chemical reaction includes changes in color, temperature, formation of gas, or the production of an odor. For example, burning sugar gives off an odor and changes color.

Front

What is a mixture?

Back

A mixture is a combination of two or more substances where each retains its own properties, such as saltwater or salad.

Front

What is the difference between soluble and insoluble?

Back

Soluble substances can dissolve in a solvent (like sugar in water), while insoluble substances do not dissolve (like sand in water).

Front

What is density?

Back

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

Front

What happens during a physical change?

Back

During a physical change, the form of a substance changes, but its chemical composition remains the same, such as ice melting into water.

Front

What is a chemical change?

Back

A chemical change results in the formation of new substances with different properties, such as rust forming on iron.