Question

The half-life period of Co is 5.26 years. Calculate the time in which its activity becomes 59% of its original value

Answer 1

Explanation:

The following formula relates the mass remaining of the radioiosotope to the original mass:

m

i

=

m

r

×

2

n

Where:

m

i

:

is the initial mass of the radioisotope

m

r

:

is the mass remaining of the radioisotope after n periods

n

:

is the number of periods

n

=

time

half life

First, find the number of periods.

n

=

15.8

years

5.26

years

n

=

3

Then plug in the values in the original formula

m

i

=

m

r

×

2

n

m

i

=

50

×

2

3

m

i

=

400

g

r

a

m

s