2. Radiating alpha or beta particles impart internal energy to the atoms, making them move faster.

4. Opposite signs. Gamma rays have no charge.

5. Larger mass, about 8000 times that of a beta particle. Hence it has about 8000 times the inertia.

7. Alpha causes the greatest change in mass number (decrease by 2) and atomic mass number (decreases by 4).

9. To over come the electrical forces that repel like charges.

11. Strong nuclear force holds it together, electrical tries to force it apart.

14. After one half-life there would be 80 counts per minute, two half-lives 40 counts per minute, 3 half-lives 20 counts per minute, 4 half-lives 10 counts per minute. So, four half-lives in eight hours gives a half life of 2 hours.

15. At 2 m the reading will be 90 counts per minute (360/2^2), at 3 m the reading will be 40 counts per minute (360/3^2).

17. Radium will lose 2 protons and 2 neutrons in an alpha decay. The result will be an atomic nucleus will have 86 protons (the atomic number = number of protons). Atomic mass will be 222 (radium will lose 4 nucleons).

18. Emitting a beta particle increases the number of protons in the nucleus by one while the number of neutrons decrease by one (the atomic mass number remains the same). Emitting an alpha particle causes a decrease of 2 protons and 2 neutrons in the nucleus.

	emit beta particle	emit alpha particle
atomic number	85	82
atomic mass number	218	214

19.

23. They exist as the produce of uranium decaying. As long as there is uranium decaying, they will exist.

27. They monitor gamma rays. The greater the exposure the darker the film upon processing.

30. No. Carbon dating is used for organic (living) matter, not inorganic (non-living) matter such as stone.