Radioactivity and half life

Question 1

How to measure stability of radioisotopes?

Answer 1

Half Life

Question 2

Define Half life:

Answer 2

Half life refers to the time it takes for a radioisotope to decay half its nuclei.

Question 3

Number Of Nuclei Remaining Formula:

Answer 3

N = No(1/2)^n
N - Final No. Nuclei
No - Initial No. Nuclei
n = T/(t1/2) - No. Half lives
T - Time taken
t1/2 - Half life

Question 4

Define Activity:

Answer 4

Activity refers to how many decays have elapsed per second. This is measured using a geiger counter. (Units Bq - Becquerels)

Question 5

Formula for Activity:

Answer 5

1. A = DeltaN/T
   A - Activity Bq
   DeltaN - Change in No. nuclei
   T - Time elapsed
2. A = Ao(1/2)^n