Erwin was measuring a radioactive substance in the laboratory. He measured 8.0 kg of substance X at noon on Tuesday. At noon on Friday, 3 days later, Erwin measured 1.0 kg of substance X. What is the half-life of substance X?
Please give some information to support your answer.
Thanks!!!
2007-05-03 06:02:25 · 3 answers · asked by Blah. Blah. Blah. RAWR! 1 in Science & Mathematics ➔ Chemistry
Tuesday noon: 8.0 kg
Wednesday noon: 4.0 kg (1/2 of 8)
Thursday noon: 2.0 kg (1/2 of 4)
Friday noon: 1.0 kg (1/2 of 2)
Saturday noon: 0.5 kg
Sunday noon: 0.25 kg
Monday noon: 0.125 kg
etc.
etc.
The half life is exactly 1 day.
.
2007-05-03 06:19:33 · answer #1 · answered by tlbs101 7 · 0⤊ 0⤋
8 kg becomes 4 kg in T, 2 kg in 2T and 1 kg in 3T and since it is given that 8 kg became 1 kg 3 days later, it goes without saying that T = 3 / 3 = 1 day. T is called the half life of the isotope.
2007-05-03 13:11:15 · answer #2 · answered by Swamy 7 · 0⤊ 0⤋
The first two answers are correct. But just to nitpick, I think the question would have been better it the quantities were given in milligrams (or even micro grams), I'm having trouble imagining what sort of decay of 4 Kilograms of material, would leave Erwin alive, or even leave his laboratory in any condition other than a boiling puddle of slag. Sure some decay processes release less energy than others, but 4kg in a day?
2007-05-03 13:40:47 · answer #3 · answered by tinkertailorcandlestickmaker 7 · 0⤊ 0⤋