PS Chemistry Midterm Review

a substance in which the atoms of two or more elements are combined in a fixed proportion.

• compound

• mixture

• element

• solution

an element used to reduce radiation exposure while taking X rays.

• lead

• aluminum

• copper

• iron

4. _______________ a type of matter with fixed composition, such as an element or compound.

• substance

• mixture

• solution

• alloy

a mixture where the particles are so small they cannot be seen with a microscope, and will not settle to the bottom of the mixture.

• solution

• suspension

• colloid

• emulsion

a type of mixture that contains particles blended evenly throughout, so you cannot see more than one part.

• homogeneous

• heterogeneous

• colloidal

• suspension

11. _______________ granite, concrete, and soup mixes are examples of this type of mixture where you can clearly see different materials.

• heterogeneous

• homogeneous

• solution

• compound

Explain how the Tyndall effect can help you tell the difference between a solution and a colloid.

• The Tyndall effect causes light to scatter in a colloid but not in a true solution.

• The Tyndall effect causes light to scatter in a true solution but not in a colloid.

• The Tyndall effect causes light to be absorbed in both a solution and a colloid.

• The Tyndall effect has no effect on distinguishing between a solution and a colloid.

Which symbol represents an element with 13 electrons?

• Al

• C

• N

• P

How many protons does Calcium have?

• a. 18

• b. 20

• c. 22

• d. 42

What is the mass number for sulfur?

• 16

• 30

• 14

• 32.06