Question

section 4.4 unstable nuclei and radioactive decay
in your textbook, read about radioactivity.
for each item in column a, write the letter of the matching item in column b.
column a

1. the rays and particles that are emitted by a radioactive material
2. a reaction that involves a change in an atoms nucleus
3. the process in which an unstable nucleus loses energy spontaneously
4. fast - moving electrons

column b
a. nuclear reaction
b. beta radiation
c. radiation
d. radioactive decay
in your textbook, read about types of radiation.
use the diagram to answer the questions.

1. which plate do the beta particles bend toward? explain.
2. explain why the gamma rays do not bend.
3. explain why the path of the beta particles bends more than the path of the alpha particles.

complete the following table of the characteristics of alpha, beta, and gamma radiation.
radiation type composition symbol mass (amu) charge

1. alpha

9.

1. high - energy electromagnetic radiation

Explanation:

1. The rays and particles emitted by radioactive material are radiation, so 1 - c.
2. A reaction involving a change in an atom's nucleus is a nuclear reaction, so 2 - a.
3. The process in which an unstable nucleus loses energy spontaneously is radioactive decay, so 3 - d.
4. Fast - moving electrons are beta radiation, so 4 - b.
5. Beta particles are negatively charged (1 - charge). Opposite charges attract, so they bend toward the positive plate.
6. Gamma rays are uncharged (no charge). Electric fields only affect charged particles, so they do not bend.
7. Beta particles are much lighter than alpha particles. According to the formula for the deflection of a charged particle in an electric field, lighter particles experience more deflection for the same force.
8. Alpha radiation: Composition is 2 protons and 2 neutrons (helium nucleus), symbol is $\alpha$, mass is 4 amu, charge is 2 +.
9. Beta radiation: Composition is fast - moving electrons, symbol is $\beta$, mass is approximately $\frac{1}{1840}$ amu, charge is 1-.
10. Gamma radiation: Composition is high - energy electromagnetic radiation, symbol is $\gamma$, mass is 0 amu, charge is 0.

Answer:

1. c. radiation
2. a. nuclear reaction
3. d. radioactive decay
4. b. beta radiation
5. Positive plate. Beta particles are negatively charged and opposite charges attract.
6. Gamma rays are uncharged, so electric fields don't affect them.
7. Beta particles are much lighter than alpha particles, so they are deflected more.
8. Composition: 2 protons and 2 neutrons (helium nucleus), Symbol: $\alpha$, Mass: 4 amu, Charge: 2+
9. Composition: Fast - moving electrons, Symbol: $\beta$, Mass: $\frac{1}{1840}$ amu, Charge: 1 -
10. Composition: High - energy electromagnetic radiation, Symbol: $\gamma$, Mass: 0 amu, Charge: 0