Question

The half-life carbon-14 is 5730 years. Archaeologists dig up a seed that contains 0.25 parts per trillion of carbon-14. If it originally contained 1 part per trillion carbon-14, how old is the archaeological specimen?

A) 11,460 years
B) 5730 years
C) 17,190 years
D) 22,920 years
E) 28,650 years

Answer 1

Answer:

A)11,460 years

Explanation:half of a radioactive element represent the time take for half of it's components to dissociate or disintegrate.

For carbonn14 that undergo an emmision to form a stable carbon 14,it moves thus

14C(1 part) ______14C(0.5 parts)_____14C(0.25parts)

i.e it undergo two radioactive decay which means two half lives .

Since each half life is 5780 years ,the age will be 2×half lives= 2×5780=11,460 years