Question

1. which nuclear process powers the sun? a. fission b. beta decay c. alpha decay d. fusion 8. which nuclear process powers nuclear power plants? a. fusion b. alpha decay c. beta decay d. fission 9. half life is a. the time it takes for a sample to decay completely. b. the time it takes for half of a sample to decay. c. the same for every isotope. d. the time for half of your life to occur. 10. the radioisotope radon - 222 has a half - life of 4 days. how much of an initial 40.0 g sample would remain after 12 days? a. 20.0 g b. 5.00 g c. 10.0 g d. 2.50 g 11. what is the half life of the isotope represented by the graph below? a. 1 day b. 2 days c. 4 days d. 10 days 12. when the nucleus of an isotope is unstable, the nucleus will spontaneously a. oxidize b. absorb electrons c. decay d. absorb protons

Explanation:

Q7 Step1: Sun's energy source

Nuclear fusion powers the sun.

Q8 Step1: Nuclear plant process

Nuclear fission powers plants.

Q9 Step1: Half-life definition

Time for half a sample to decay.

Q10 Step1: Calculate half-lives

n = 12/4 = 3 half-lives.

Q10 Step2: Compute remaining mass

40.0g*(1/2)^3 = 5.00g.

Q11 Step1: Find half count

Initial count=80, half=40.

Q11 Step2: Read graph time

Count=40 at ~2 days.

Q12 Step1: Unstable nucleus behavior

Unstable nuclei decay spontaneously.

Answer:

1. d. fusion
2. d. fission
3. b. The time it takes for half of a sample to decay.
4. b. 5.00 g
5. b. 2 days
6. c. Decay