Question

Find the radioactivity of a 1 g sample of 226Ra given that
`t_(1/2)=1620` years and Avogadro's number = 6.023 ×
`10^(23)`.

Answer 1

Step-by-step explanation:

No of atoms of Ra in 1 g of sample = 6.023 x 10²³ / 226

N = 2.66 x 10²¹

disintegration constant λ = .693 / half life

half life = 1620 x 365 x 60 x 60 x 24 = 5.1 x 10¹⁰ s

disintegration constant λ = .693 / 5.1 x 10¹⁰

radioactivity dn / dt = λN

= (.693 / 5.1 x 10¹⁰ ) x 2.66 x 10²¹

= .3614 x 10¹¹ per sec

= 3.614 x 10¹⁰ / s