Question

1. The radioactive source you will be working with in this lab is Cs-137. Look up the half-life of this material and report the value in units of seconds. 2. The relationship between decay constant (l) and half-life is:

Answer 1

The question is incomplete, here is the complete question:

1. The radioactive source you will be working with in this lab is Cs-137. Look up the half-life of this material and report the value in units of seconds.

2. The relationship between decay constant (l) and half-life is:

`t_(1/2)=(\ln 2)/(k)`

For Cs-137, what is the value of 'k' in
`s^(-1)`

Answer:

For 1: The half life for Cs-137 isotope is
`9.51* 10^8s`

For 2: The rate constant of Cs-137 isotope is
`7.29* 10^(-10)s^(-1)`

Step-by-step explanation:

• For 1:

Half life is defined as the time taken for half of the reaction to complete. This is also defined as the time in which the concentration of a reactant is reduced to half of its original value.

The half life for Cs-137 isotope is
`9.51* 10^8s`

• For 2:

The relationship between decay constant (l) and half-life is: given by the equation:

`t_(1/2)=(\ln 2)/(k)`

where,

`t_(1/2)` = half life of Cs-137 isotope =
`9.51* 10^8s`

k = rate constant

Putting values in above equation, we get:

`9.51* 10^8s=(\ln 2)/(k)\\\\k=(\ln 2)/(9.51* 10^8)=7.29* 10^(-10)s^(-1)`

Hence, the rate constant of Cs-137 isotope is
`7.29* 10^(-10)s^(-1)`