8th grade Science Final exam review

Front

What word describes when water is attracted to other substances?

Back

Adhesion: The tendency of water molecules to be attracted to other substances, allowing it to spread and wet surfaces.

Front

What does the Law of Conservation of Mass state?

Back

The Law of Conservation of Mass states that in a chemical reaction, mass cannot be created or destroyed, only rearranged.

Front

How many atoms of each element are in NaCl?

Back

Na=1, Cl=1: Sodium chloride (NaCl) consists of one sodium atom and one chlorine atom.

Front

What color is a star with a surface temperature of 30,000 K?

Back

Blue or blue-white: Stars with high surface temperatures emit blue or blue-white light.

Front

What type of energy transfer causes warm air to rise and cold air to sink?

Back

Convection: The transfer of heat through the movement of fluids (liquids and gases), causing warm air to rise and cold air to sink.

Front

What is cohesion in relation to water?

Back

Cohesion: The attraction between water molecules, which causes them to stick together.

Front

What is the definition of conduction?

Back

Conduction: The transfer of heat through direct contact between materials.

Front

What is radiation in terms of energy transfer?

Back

Radiation: The transfer of energy through electromagnetic waves, such as sunlight.

Front

What is the formula for calculating density?

Back

Density = Mass/Volume: Density is the mass of an object divided by its volume.

Front

What is the difference between a physical change and a chemical change?

Back

Physical Change: A change that affects one or more physical properties of a substance without altering its chemical composition. Chemical Change: A change that results in the formation of new chemical substances.