# Half Life

DOES ANYBODY UNDERSTAND THE CONCEPT OF HALF LIFE!?

I JUST DONT GET IT. please if you could help me understand i'd be very grateful :) **

Posted Tue 31st May, 2011 @ 19:35 by Zara

## 5 Answers

It's the time it takes for half of the atom to have decayed.

For example: atom X has a half life of 1 year. After 1 years, half of it will have decayed leaving only 1/2 of it. After 2 years, half of what's left (1/2) will have decayed leaving only 1/4 of the original atom left. After 3 years, only 1/8 of the original atom will be left. 1/16 after 4 years, 1/32 after 5 years, etc.

Answered Sun 5th June, 2011 @ 00:33 by Maleficent

It can also be described as the time it takes the count rate of a radiative sample to fall to half its initial amount ; thats the glossary answer that the examiners want

Answered Wed 1st June, 2011 @ 08:24 by Lamise Hassan

the amount of time it takes for the radioactive atom to decay by half. the decaying activity is measured in becquerels. e.g te half life of an atom is 10 hours therefore in 20 hours 1/4 of the atom hasn't decayed.

Answered Fri 3rd June, 2011 @ 15:04 by Lottie

the half life of something is the time it takes for the radioactivity of it to decrease by half not half its life.

Answered Wed 1st June, 2011 @ 19:10 by Pui Pui

Basically, half of the redioactive life of an unstable atom.

e.g. Irridium -81 will have a life of 16 days, but it's half life is 8 days.

We say half life because after half it's life it has nearly fully disintergrated, and it is too unstable.

Answered Tue 31st May, 2011 @ 19:58 by Al