Question

$C^{14}$ is

• A. a natural non-radioactive isotope
• B. an artificial non-radioactive isotope
• C. an artificial radioactive isotope
• D. a natural radioactive isotope

Answer 1

Answer: (D)

Carbon has three important isotopes $C^{12},C^{13}$ and $C^{14}\cdot C^{14}$ is formed as traces in the atmosphere by cosmic neutron bombardment of nitrogen
${}_7{N}^{14}+{}_0{n}^1⟶{}_6{C}^{14}+{}_1{H}^1$
$C^{14}$ is a natural radioactive isotope.