Question

What is the concept of a half life?

Answer 1

@chmvijay

Answer 2

alright lets say you have 50g of bismuth-209 in 4.6×10^19 years you will have 25g of bismuth

Answer 3

ok so that is how long it takes for half of it to disappear... where does it go?

Answer 4

It will never totally disappear. It will approach an asymptote. 1/2 times 1/2 times 1/2 will become 1/16. It will get smaller and smaller.

Answer 5

Oh, so it shrinks in volume, but where does it go?

Answer 6

The element will decay into another element. Think of it in terms of stability. Uranium is highly unstable,therefore radioactive, will emit energy in terms of alpha, 2 proton AND 2 electrons, or beta decay, 1 proton OR on electron, until it becomes a stable nucleus.

Answer 7

Oh, okay, that makes sense :)
so does everything have a half-life or only the ones that are unstable?

Answer 8

A change in proton number will means it will become a different element. Example Hydrogen has one proton, helium has 2 protons.

Whereas a different number of neutrons will be an isotope of the same element

And a different number of electrons will either become a negative or positive charge ion.

Answer 9

ok, thanks that makes so much more sense! :D

Answer 10

I believe everything has a half life. Just really long ones, in terms of millions of years. Like plastic... That will never go away.

Answer 11

an easy way to remeber half life is to say you stand 12 feet from the wall now then walk half way to the wall you are now 6 feet from the wall technically like half life you will never reach the wall and that wall like ngomd said is an asymptote

Answer 12

ok! yay, now I get it thanks so much :D

Answer 13

thank you to both of you :D