1. Half-Life Skill Builder Sheet Init 10/19/2016 by Daniel R. Barnes
Based on a previously-created worksheet

2. temperature
time
time
triangle
“change in time” = “time elapsed” = “time gone by”
decay
life
short
long

3. francium-223, astatine-210
uranium-238, potassium-40
random 50
50%
5730
potassium-40
50%

4. 50%
50%
decay
500
250
125
zero
radioactive
half-lives

5. 0.5
0.25
0.125
0.0625
12,000 y / 5730 y/HL = 2.09 HL
3 HL x 22 min/HL = 66 minutes
2100 My / 700 My/HL = 3 HL
7 HL x y/HL = y

6. 12,000 y / 5730 y/HL = 2.09 HL  2 HL to make the math easy
1000 mg x (½)2 = 1000 mg x ¼ = 1000 mg x 0.25 = 250 mg
2 d x 24 h/d = 48 h
48 h / 8 h/HL = 6 HL (8.1  8)
64 g x (½)6 = 64 g x 1/64 = 64 g x = duh. 1 g. (64/64 = 1!)
40 kg / 2.5 kg = 16 = 24  4 half-lives
4 HL x 24,100 y/HL = 96,400 y