Nuclear Power Engineering
The atomic mass of an element is fractional, because

It contains neutrons
It may have isotopes
Of uncertainty principle
It may have isobars

ANSWER DOWNLOAD EXAMIANS APP

Nuclear Power Engineering
The half life period of a radioactive substance is best determined by counting the number of alpha particles emitted per second in a Geiger Muller counter from its known quantity. If the half life period of a radioactive substance is one month, then

L/8th of it will remain intact at the end of four months
3/4th of it will disintegrate in two months
It will completely disintegrate in two months
It will completely disintegrate in four months

ANSWER DOWNLOAD EXAMIANS APP