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1. How are science and technology related?
Technology is a branch of natural science.
Science is a branch of technology.
Advances in science may lead to advances in technology and vice versa. *********
Science and technology are not related.

2. Why are scientific models important?
They prove scientific theories.
They help visualize things that are very complex, very large, or very small.*******
They make it harder to understand things.
They never change.

3. How do scientists communicate the results of investigations? (1 point)
by publishing articles in scientific journals
by giving talks at scientific conferences
by exchanging e-mails
all of the above ******

4. The type of graph used to show how a part of something relates to a whole is a (1 point)
circle graph. *********
bar graph.
line graph.
direct proportion.

5. A substance that has a high reactivity (1 point)
easily combines chemically with other substances. ************
burns in the presence of water.
displaces dissolved oxygen.
has a high boiling point.

6. A substance that is made up of only one kind of atom is a(n) (1 point)
compound.
element. **********
homogeneous mixture.
solution.

7. A mixture can be classified as a solution, suspension, or colloid based on the (1 point)
number of particles it contains.
size of its largest particles. *********
color of its particles.
size of its smallest particles.

8. Which of the following is a chemical change? (1 point)
ice melting
ice being carved
water boiling
water breaking down into hydrogen and oxygen **********

9. A gas has (1 point)
a definite volume but no definite shape.
a definite shape but no definite volume.
no definite shape or definite volume.*********
a definite volume and definite shape.

10. The temperature and volume in a closed container of gas remain constant. If the number of particles of gas is increased, the gas pressure will (1 point)
increase.******
decrease.
remain constant.
cause a decrease in the average kinetic energy of the particles.

11. During what phase change does the arrangement of water molecules become more orderly? (1 point)
melting
freezing**********
boiling
condensing

12. Which of the following is NOT part of John Dalton’s atomic theory? (1 point)
All elements are composed of atoms.
All atoms of the same element have the same mass.
Atoms conatin subatomic particles.***********
A compound contains atoms of more than one element.

13. Which subatomic particle has a negative charge? (1 point)
electron ************
alpha particle
neutron
proton

14. One-twelfth the mass of a carbon-12 atom used to define a(n) (1 point)
atomic number.
atomic mass.
mass number.
atomic mass unit.***********

15. As you move from left to right across a period, the number of valence electrons (1 point)
increases.*********
stays the same.
increases and then decreases.
decreases.

16. Typically, atoms gain or lose electrons to achieve (1 point)
an exchange of energy.
ionization.********
a stable electron configuration.
vaporization.

17. Which statement about metals is true? (1 point)
A metal lattice is extremely rigid.
A metal lattice has weak bonds within a metal.
Electrons in a metal lattice are free to move.***********
Generally, metals have a low melting point.

18. Which of the following is a balanced chemical equation for the synthesis of NaBr from Na and Br2? (1 point)
Na + Br2 — NaBr
2Na + Br2 — NaBr
Na + Br2 — 2NaBr
2Na + Br2 — 2NaBr*********

19. When the forward and reverse paths of a change occur at the same rate, (1 point)
the system is conserved.
the system is in equilibrium.********
the change must be physical.
the change must be chemical.

20. A base is defined as a compound that produces (1 point)
hydroxide ions in solution.********
hydrogen ions in solution.
hydronium ions in solution.
sodium ions in solution.

21. A substance that ionizes or dissociates into ions when placed in water is always a(an) (1 point)
conductor.
electrolyte.
strong acid.********
strong base.

22. A girl tasted each of the following foods. Which of the following would NOT taste acidic to her?
(1 point)
lime
tomato
orange
celery******

23. Which of the following statements is true? (1 point)
Chemical reaction rates vary with the conditions of the change, but nuclear rates do not.******
Nuclear decay rates vary with the conditions of the change, but chemical reaction rates do not.
Both chemical reaction rates and nuclear decay rates vary with the conditions of the change.
Neither chemical reaction rates nor nuclear decay rates vary with the conditions of the change.

24. What type of nuclear decay produces energy instead of a particle? (1 point)
alpha decay
beta decay
gamma decay*******
electron d