Chapter 20, Problem 20.24QP

Interpretation Introduction

Interpretation:

The half-life period of ${\text{Y}}^{90}$ should be calculated by using the given data.

Concept Introduction:

Radioactive decay:

• Thisprocess is the accompanied by the emission of one or more than one types of ionizing radiation like alpha ,beta, neutron, particles and gamma rays are disintegrate
• Radio active life-it refers to the amount of time taken by completion of half of its original isotope to decay. The rate of decay is a fixed rate called half-life.
• Half-life used in carbon dating-technique forthe age calculation of dead wood fossil, monument old tree etc.
• The half-life period s are determined by considering carbon dating technique.
• Carbon dating uses the half-life of carbon-14 to find the approximate age of an object. It’s may be 40.000 year old or younger.
• Radioactive isotope: An atom in a chemical compound is replaced by another atom, of the same chemical element. This is the principle behind the radioactive tracers.

  Titanium is the example of radioactive isotope.

Given:

${\text{Y}}^{90}$ have activity 9.8 $\times {10}^5$ disintegration/minute at $\text{1:00 p}\text{.m}\text{., 12/3/10}$

At $\text{2:15 p}\text{.m}\text{., 12/17/10}$, activity measured is $2.6\times {10}^4$ disintegration/minute.

Formula:

Half –life period:

${\text{t}}_{\text{1/2}}\text{=}\frac{\text{0}\text{.693}}{\text{k}}$

For identifying k or t value:

$\text{ln}\frac{{\text{N}}_{\text{t}}}{{\text{N}}_{\text{0}}}\text{=-kt}$