Of the following, the one that is not an example of a suspension is
a. milk
b. milk of magnesia
c. sand in water
d. sugar in water

2. the word used to represent a chemical reaction is a/an
a. atom
b. formula
c. equation
d. symbol

3. when two similarly charged objects are brought close together, they
a. repel each other
b. have no effect on each other
c. stick to each other
d. attract each other

4. an element common to all acids is
a. chlorine
b. hydrogen
c. nitrogen
d. oxygen

5. atoms of the same element that differ slightly in mass are called
a. ions
b. isotopes
c. neutrons
d. positrons

6. in general, salts
a. contain hydroxide ions
b. contain hydrogen ions
c. are ionic compounds
d. turn blue litmus red.

7. a dye used to test the acidity of a substance is
a. litmus
b. magnesium sulfate
c. sodium chloride
d. sodium hydroxide

8. the central portion of an atom is called the
a. electron
b. nucleus
c. ring
d. shell

9. sugar is poured into a glass of water and stirred. in this example the sugar is the
a. solution
b. solvent
c. solute
d. alcohol

10. which of the following is characterized by a sour taste?
a. bases
b. acids
c. salts
d. compounds

11. which of the following is characterized by a bitter taste and turn lithmus blue?
a. bases
b. acids
c. compounds
d. elements

12. the force of gravity on an object is called
a. density
b. mass
c. volume
d. weight

13. the liquid referred to as the “universal solvent” is
a. alcohol.
b. benzene.
c. oil.
d. water.

14. a statement that proposes a cause-and-effect relationship between two variables is called:
a. conclusion.
b. fair test.
c. hypothesis.
d. theory

15. any substance that has mass and occupies space is called
a. a gas
b. a liquid
c. matter
d. a solid

16. when the numbers of electrons and protons in a sample of matter are equal, the matter is
a. insulated.
b. negatively charged.
c. neutral.
d. positively charged.

17. which of the following is most important when judging the quality of a scientific theory?
a. the quality and reliability of data that support the theory
b. the amount of detail provided in the theory
c. how recently the theory has been published
d. the respectability of the scientists setting forth the theory

18. substances that cannot be decomposed to any simpler substances are called
a. compounds.
b. elements.
c. mixtures.
d. none of the above.

19. when the air in a bell jar containing a ringing bell is removed, the sound decreases because
a. the removal of the air prevents electric current from flowing
b. sound cannot travel through the air
c. sound cannot travel through glass
d. sound cannot travel in a vacuum

20. an element common to all acids is
a. chlorine.
b. oxygen.
c. nitrogen.
d. hydrogen.

21. the amount of matter in an object is best expressed by its
a. density
b. mass
c. volume
d. weight

22. a substance that increases the rate of a reaction is a
a. liquid
b. gas
c. catalyst
d. solid