The half-life of a radioactive substance is 10 days. This means that

Options

A. the substance completely disintergrates in 20 days
B. the substance completely disintergrates in 40 days
C. `1//8` part of the mass of the substance will be ledt intact at the end of 40 days
D. `7//8` part of the mass of the substance disintegrates in 30 days

Answer

D

Explanation

(d) In 30 days (i.e., half lives)
So, `(1)/(2^(3)) = (1)/(8)` of the substance is left of `(7)/(8)` part of the mess of the substance disintegrate.