Question

Choose the material on which \(^{14}C\) dating technique can be correctly applied.

• A. Charred food grains from the Indus Valley civilization
• B. Organic matter in carbonaceous chondrites
• C. Diamonds from the Earth's interior
• D. Graphite from Proterozoic sedimentary basins

Hint:

Carbon dating can only be applied to organic material. It cannot be used for ancient inorganic substances like diamonds or graphite.

Answer 1

The Correct Option is A

Step 1: How carbon-14 dating works.
The $^{14}C$ method dates things that were once living and held carbon. It works only up to about fifty thousand years, since after that too little $^{14}C$ is left to measure.

Step 2: Two rules to apply.
The sample must contain real organic carbon, and it must be young enough to fall inside the fifty thousand year limit.

Step 3: Reject the very old samples.
Carbonaceous chondrites are billions of years old, far past the limit. Graphite from Proterozoic basins is also far too old and its carbon is locked up. So both fail the age test.

Step 4: Reject the diamonds.
Diamonds grow deep inside the Earth and are extremely old. Any $^{14}C$ in them is long gone, so they cannot be dated this way.

Step 5: Choose the charred grains.
Charred food grains from the Indus Valley are only a few thousand years old and are full of organic carbon. They fit both rules perfectly.
\[ \boxed{\text{Charred food grains from the Indus Valley civilization}} \]