Chapter 20, Problem 20.28QP

Interpretation Introduction

Interpretation:

The age of charcoal should be determined by using the given data.

Concept Introduction:

• Radioactive decay:
• This process 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 for the 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.

Formula:

Half –life period:

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

For identifying k or t value:

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

Given:

A piece of charcoal found at volcanic site is $\text{11}\text{.2dis/sec}$.

Activity of carbon 14 in an equal mass of living matter is $\text{18}\text{.3dis/sec}$.

To determine: The age of charcoal is calculate by considering the carbon-14 decay.