[A]A flag waving in the wind
[B]A glass jar sitting on a shelf
[C]A ball rolling along a sidewalk
[D]A battery powering a radio
2. Which of these best describes the particle motion taking place as CO2 gas is exposed to freezing temperatures?
[A]The motion of the particles becomes random
[B]The particles decrease in speed
[C]The particles moves with more force
[D]The motion of the particles is unchanged
3. What is the normal heart rate of adults at rest?
[A]72 beats per minute
[B]70 beats per minute
[C]66 beats per minute
[D]62 beats per minute
4. How is the modern model of an atom different from the Bohr atomic model?
[A]The masses of the atomic particles are different
[B]The arrangements of the electrons are different
[C]The numbers of electrons are different
[D]The shapes of the nuclei are different
5. It is important to protect air quality because _____________________________.
[A]Storms worsen as air pollution decreases
[B]Energy produced by the sun decreases when air is polluted
[C]Acid rain is caused by air pollution
[D]Wind currents change when the air is polluted