Half-life (t½)

Question 1

What is half-life (t½)?

Answer 1

The half-life is the time taken for the:
activity
mass
or number of nuclei
Of a radioisotope to halve.

Question 2

Is the half-life of a radioisotope affected by external conditions?

Answer 2

The half-life of a radioisotope is not affected by external conditions such as chemical changes, temperature, pressure or the physical state (solid, liquid, gas or solution) of the sample.

Question 3

What is the radioactive decay curve?

Answer 3

A graph showing how count rate of a radioisotope decreased with time and it will always have the same curve. For any particular radioisotope, the count rate and time will be different but the shape of the curve will be the same. This is known as a radioactive decay curve.

Question 4

What is the time taken for any radioactive source to decrease by half?

Answer 4

For any radioactive source the time taken for the activity to decrease by half is always the same.

Question 5

What does the use of radioisotope depend on?

Answer 5

How a radioisotope can be used often depends on its half life.