Chapter 19, Problem 30A

Interpretation Introduction

Interpretation: The reason why an ancient wood or cloth artifact contains less carbon-14 than recently fabricated articles made of similar materials has to be explained.

Concept introduction: A process for dating ancient articles made from wood or cloth is called radiocarbon dating (or) carbon-14 dating. Radiocarbon dating is based on $\text{C}$ that decays by the production of $\beta \text{-}$ particles.

  $\text{C}\to e+\text{N}$

When neutrons of high energy from space collide with nitrogen-14, carbon-14 is produced in the atmosphere.

  $\text{N}+n\to \text{C}+\text{H}$

The half-life of $\text{C}$ is $\text{5,730}$ years.

Answer to Problem 30A

When an organism dies, it no longer replenishes itself with carbon-14 from the atmosphere. As the carbon-14 undergoes decay, the amount decreases over time. This assumes that the concentration of carbon-14 in the atmosphere is constant over time.

Explanation of Solution

A method for dating ancient articles made from wood or cloth is called radiocarbon dating (or) carbon-14 dating. The nuclide that is used in dating artifacts is carbon-14 $\left(\text{C}\right).$

Radiocarbon dating is based on $\text{C}$ that decays by the production of $\beta \text{-}$ particles.

  $\text{C}\to e+\text{N}$

When neutrons of high energy from space collide with nitrogen-14, carbon-14 is produced in the atmosphere.

  $\text{N}+n\to \text{C}+\text{H}$

The half-life of $\text{C}$ is $\text{5,730}$ years.

Carbon-14 could be used to date wood and cloth artifacts because carbon-14 along with other isotopes of carbons reacts with oxygen to form carbon dioxide.

When an organism dies, it no longer replenishes itself with carbon-14 from the atmosphere. As time passes, the amount of carbon-14 in the artifact decays in a smaller amount. The remaining amount of carbon-14 in an artifact tells the amount of time that is passed between the period the plant was alive and the current age.