Question

how long will it take for 100 grams of a substance with a half life of 2 years to decay to a mass of 50 grams?

Answer 1

A half life of 2 years means the mass will half every two years. After two years the 100 grams will become 100/2 = 50 grams. Therefore it will take 2 years to decay to a mass of 50 grams.

Answer 2

Answer: 2 years.

Step-by-step explanation:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Half life is represented by
`t_{(1)/(2)`

`t_{(1)/(2)=(0.693)/(\lambda)`

`\lambda` = rate constant

As the initial amount of 100 grams is decaying to mass of 50 grams which is half of initial value, it will take 2 years for the decay.