Iron - 59 has a half life of 45.1 ayes. How old is an iron nail if the Fe -59 content is 25% that of a new sample of iron ? Please show me all the calculation to understand.

Question

arihangdu · Answer

Please help me I will give medals and fans.

vocaloid · Answer

amount left = original amount*(1/2)^(total time/length of half-life)

so plugging in our numbers, we get:

.25 = (1/2)^(t/45.1)
solve for t

arihangdu · Answer

How to solve please help me

vocaloid · Answer

.25 = (1/2)^2

so

(1/2)^2 = (1/2)^(t/45.1)

2 = t/45.1

solve for t

arihangdu · Answer

T= 45.1 x  2= 90?

arihangdu · Answer

Right?

vocaloid · Answer

90.2 but yeah

arihangdu · Answer

Any formula we need to use here please?

vocaloid · Answer

no, that's it, t = 90.2 years...

arihangdu · Answer

Days or years ?

arihangdu · Answer

A=Ao *m this not a decays formula ?or I confused !,

arihangdu · Answer

Ok thank you so much for helping

arihangdu · Answer

Please receive my appreciation.

arihangdu · Answer

Thanks for helping me.

arihangdu · Answer

I don't know how you do this steps 
.25= 1/2^t/45.1
1/2^2=1/2)^t/45.1