Given a sample of radioactives substance, if half the material takes 10 years to decay to a non radioactive material, what is the rate of decay?
Given 1 ton of material, how long until 0.1% remains?
2006-09-28 03:01:50 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
we have to find n such that 1(/2)^n > 1/1000 but (1/2)(n+1) < 1/1000
so n = 9
so after 9 half lives remmaining > .1% but after 10 < .1% so around 10 half lives or 100 years
2006-09-28 05:03:26 · answer #1 · answered by Mein Hoon Na 7 · 0⤊ 0⤋
The half-life is the rate at which HALF the radioactive sample will decay to something else (could be radioactive, could not be). So, if it takes 10 years for half to decay, the half-life is 10 years.
2006-09-28 10:42:35 · answer #2 · answered by Will S 2 · 0⤊ 0⤋
2 * 10 =20 years FOR ALL
1 ton=1000 kg.
1000*0.1=100 kg. will remain.
1000-100=900 kg. must decay.
1000kg (0 years at the beginning)
500 kg 10 years
250 kg 10
125 kg 10 years
62,5 kg 10 years
answer: 40 years.
2006-09-28 10:46:38 · answer #3 · answered by iyiogrenci 6 · 0⤊ 0⤋