Review 1

When changing from a gas to a liquid, the temperature of a substance would be at the ________ point.

• melting

• freezing

• evaporation

• condensation

Look at the following chemical equation. Na + Cl₂ -> ?

How many Cl atoms must there be in the products?

• 1

• 2

• 3

• 4

Melting and freezing occur in the same range of temperature on a heating scale.

• True

• False

A mixture like coffee that looks the same throughout is a ______.

• element

• homogeneous mixture

• compound

• heterogeneous mixture

This substance is a _______.

• element

• homogeneous mixture

• compound

• heterogeneous mixture

As a solid melts, what BEST describes what happens to the particles?

• Atoms slow down and come together.

• Atoms speed up and move past one another.

• Atoms vibrate in place.

• Atoms lose electrons.

If you mix 20 grams of sodium with 38 grams of chlorine, how much salt should you get?

• 8 grams

• 38 grams

• 58 grams

• 20 grams

Particles become more dense in ______ and _______.

• melting and freezing

• evaporation and freezing

• evaporation and melting

• freezing and condensing

This substance is __________.

• an element

• a homogeneous mixture

• a compound

• a heterogeneous mixture

Which of the following could be an actual reaction?

• 2Zn + O --> 3ZnO

• Zn₂ + O₂ --> ZnO

• 2Zn + 3O_{2 -->} 6ZnO

• 2Zn + O₂ --> 2ZnO