Question

A sample of sodium-24 decays to 1/16of its original size in 60 hours. What is the half-life of Na-24

Answer 1

Answer:

The correct answer is - 15 hours.

Explanation:

Half-life an element is the time required to decay the half amount of the initial amount of the element and is represented by t1/2.

The formula for the calculating initial amount

n(i)=n(r)⋅2^n

where

n(i) - the initial number of moles of element

n(r) - the number of moles remained amount after the given time

n - the number of periods,

=  time T, where T is the half-life.

n(i)=n(r)⋅2^n

n(i)/n(r) =2^n

1/16 =2^n

n= 4

The half life = 60/n

= 60/4

= 15 hours.