Question

0110 For an unknown element the wavelength recorded is 2.9x104-2 m, the half life of element is __years А 50 B 100 D 47. с ,​

Answer 1

Given: The wavelength recorded for an unknown element is $=2.9*10^{-2}m$

To find: The half-life of the element.

Solution:

We know that the half-life of an element is the time required for a radioactive particle to decay.

We have been given,

The wavelength recorded for the unknown element is $=2.9*10^{-2}m$

Let us take half-life to be $T_\frac{1}{2}$

The formula for half-life, wavelength, and decay constant is,

$T_\frac{1}{2}=\frac{ln2}{wavelength}$

Wavelength(λ) = $2.9*10^{-2}$

The value of decay constant (ln 2) = $0.693$

∴ The half-life will be,

$T_\frac{1}{2} = \frac{0.693}{2.9*10^{-2}}$

⇒ $T_\frac{1}{2}=23.9$

⇒ $T_\frac{1}{2} = 24$

Final answer:

The half-life recorded for the element is 24 years.

Answer 2

Answer:

Explanation:Todayshoes can u please tell me from which book u have taken this question.