Question

The half life of radium is 1600 years.How much time does 1gm of radium take to reduce to 0.125g

Answer 1

1/2 × 1 = 0.5 gm
0.125/0.5 = 1/4
1/2 + 1/4 = 3/4
full life of radium = 1600 × 2 =3200
3/4×3200
= 2400 yes
it will take 2400 yrs to reduce to 0.125 gm

Answer 2

Answer: 4800 years

Explanation:

For 1 gm to reduce 0.125 g,

1 gm ÷ 0.125 g = 8

In terms of half-life:

⇒8 = 2³

Thus,  it will take 3 half lives for 1 g of radium to reduce to 0.125 g

So, number of years = 3 ×1600 years = 4800 years