Answer:
(a) A = (20mg)/(2^(t/30))
(b) 12.6mg
(c) 129.6years
Step-by-step explanation:
To calculate the amount remaining after a number of half-lives, n, we can make use of:

Where A = amount remaining
B = initial amount

(a) A = (20mg)/(2^(t/30))
(b) Mass after 20years
A = (20mg)/(2^(20/30)) ≈ 12.6mg
(c) After how long will only 1mg remain:
1mg = (20mg)/(2^(t/30))

Taking log of both sides we have:
Log(20) = (t/30)log(2)
t/30 = (log(20))/(log(2)) ≈ 4.3
t/30 = 4.3
t = 30 x 4.3 ≈ 129.6years.
Hello there!
The answer is: 40,000 + 8,000 + 60 + 7 = 48,067.
Hope this helped!!
Answer:
300 times
Step-by-step explanation:
600 * 1/2 = 600/2
=300
Answer:
58.86 mg
Step-by-step explanation:
8 mg = 16 kg
1 kg = 2.2 lb
use substitution
8 mg = 16 (2.2 lb)
8 mg = 35.2 lb
8 mg / 35.2 lb = x mg / 259 lb
2072 = 35.2 x
x = 58.86 mg