Question

If a radioisotope has a half life of 10 years, how much of the original material would remain after 40 years?
A.

One-eighth

B.

One-tenth

C.

One-half

D.

One-sixteenth

Answer 1

half life of 10 years, means, the quantity becomes half in 10 years

Answer 2

After 10 years ---- > \(\large \frac{1}{2} \)

Answer 3

So answer C?

Answer 4

After 20 years ---- > \(\large \frac{1}{2} \times \frac{1}{2} \)

Answer 5

After 30 years ---- > \(\large \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} \)

Answer 6

After 40 years ---- > ?

Answer 7

Oh i see. thank you

Answer 8

np :) every 10 years, it becomes half of watever it was before... it goes on reducing like that