PLS ANSWER IMMEDIATLY

1. One isotope of Br has a half-life of 16.5 hours. How much of a 2.00-gram sample remains at the end of 1.00 day?

2. The symbol for an electron also used to represent a(n)

   1. a) Alpha particle
   2. b) Beta particle
   3. c) Positron
   4. b) Gamma-ray

3. The half-life of a radioactive isotope

   1. a) Changes over time
   2. b) Is Constant
   3. c) Is a characteristic of stable isotopes
   4. d) Decreases in value as time passes

Directions: Answer each of the following questions.

1. One isotope of Br has a half-life of 16.5 hours. How much of a 2.00-gram sample remains at the end of 1.00 day?

2. If 160 grams of a 200-gram sample of gold-198 decay in 6.25 days, what is the half-life of gold-198?

3. The symbol for an electron also used to represent a(n)

a. Alpha particle

b. Beta particle

c. Positron

d. Gamma-ray

4. During a fission reaction:

a. A larger and more stable nucleus is formed

b. Energy is absorbed

c. Positrons are always released

d. Smaller and more stable nuclei are formed

5. The half-life of a radioactive isotope

a. Changes over time

b. Is constant

c. Is a characteristic of stable isotopes

d. Decreases in value as time passes

6. Radioactive dating is used to determine the

a. Half-life of a radioactive isotope

b. Type of particle emitted by an isotope as it decays

c. Age of a specimen

d. Time required for half of a radioactive sample to decay

7. Carbon-11 has a half-life of 20 minutes. Explain what this means.

8. Conduct research to identify two naturally occurring radioactive elements and two synthetic radioactive elements.

CRITICAL THINKING:

9. Conduct research to explain how fusion differs from fission. How are the two processes alike? How are they different? (Compare and contrast) Don’t forget to cite your resources.

20. When a particular isotope undergoes natural radioactive decay, what can it emit? a. alpha particle b. beta particle c. an alpha particle and a gamma ray d. a beta particle and a gamma ray e. all of the above