Question

Technetium-104 has a half-life of 18.0 minutes. How much of a 165.0 g sample remains after 36.0 minutes?

Answer 1

41.25g

Step-by-step explanation:

Given parameters:

Half-life of Technetium - 104 = 18minutes

Mass = 165g

Unknown:

Mass of sample remaining after 36minutes = ?

Solution:

The half-life of a radioactive element is the time taken for half of the element to decay;

Now;

Start First half life Second half-life

Time 0 18min 36min

Mass 165g 82.5g 41.25g