# NEET Physics Nuclei Questions Solved

A radioactive substance has an average life of 5 hours. In a time of 5 hours
(a) Half of the active nuclei decay
(b) Less than half of the active nuclei decay
(c) More than half of the active nuclei decay
(d) All active nuclei decay

(c) If $\mathrm{\lambda }$ is the decay constant of a radioactive substance than average life = $\frac{1}{\mathrm{\lambda }}$
Also half life =
in single average life, more than 63% of radioactive nuclei decay

Difficulty Level:

• 12%
• 17%
• 56%
• 17%
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