What is the atomic number of this atom?

• 2
• 4
• 6
• none of the above

A pure substance that cannot be broken down into any other substance.

• Elements

• Compounds

• Mixtures

A(n) ______________ is formed when two or more elements chemically combine.

• Compound

• Element

• Mixture

A ___________ is a combination of many different elements not chemically combined.

• Element

• Compound

• Mixture

What makes elements and compounds different from mixtures? Elements & compounds-

• have a constant composition (pure substances)

• are made of gases

• Will not change when heated

• conduct electric current

Which of the following are true about the Kinetic Molecular Theory?

• Matter is made of particles

• Particles are moving

• The phase of matter determines how fast the particles move

• Particles are mostly still

Which of the following are true about phase changes?

• They are reversible

• They are physical changes

• They are chemical changes

• A substance retains its identity

How do we determine phase changes?

• By looking at the heat that is released

• By measuring the temperature

• By observing the chemical structure

Which of the following phase changes include heat being added?

• Melting

• Sublimation

• Deposition

• Condensation

Which of the following phase changes involve heat being removed?

• Deposition

• Vaporization

• Condensation

• Evaporation