Ok, I don't know how to answer this question for chemistry and I don't know how to do the problem...help please?
Strontium-90 has a half-life of 28 years. If a 1.00-mg sample were stored for 112 years, what mass of Sr-90 would remain?
2006-10-14 11:45:00 · 10 answers · asked by naddawannabee 1 in Science & Mathematics ➔ Chemistry
112 years/28 years per half life = 4 half lifes
Half is lost each half life
Hence remaining is 1/2 x 1/2 x 1/2 x 1/2 x 1.00mg = 0.00625mg
2006-10-14 12:04:00 · answer #1 · answered by L. A. L. 6 · 2⤊ 0⤋
In 28 years 1.00/2 = 0.05 mg of Strontium will remain.
In 2*28 = 56 years 0.05/2 = 0.025 mg of Strontium will remain.
In 3*28 = 84 years 0.025/2 = 0.0125 mg of Strontium will remain.
In 4*28 = 112 years 0.0125 = 0.00625 mg of Strontium will remain.
2006-10-14 11:51:15 · answer #2 · answered by Dimos F 4 · 2⤊ 0⤋
A half life is how long it takes for 1/2 of a sample to decay...
after 28 years, you'd have 0.5 mg
after 56 (28+28) years, you'd have 0.25 mg
after 84 (28+28+28) years, you'd have 0.0125 mg
after 112 years (28 + 28 + 28 + 28) years, you'd have 0.00625 mg
2006-10-14 11:49:23 · answer #3 · answered by Mr. G 6 · 4⤊ 0⤋
I am seeing decimal errors in other responses.
1.00 mg divided by 2 (28 years) is 0.50 mg
0.50 mg divided by 2 (56 years) is 0.25 mg
0.25 mg divided by 2 (84 years) is 0.125 mg
0.125 mg divided by 2 (112 years) is 0.0625 mg
answer: 0.0625 mg
2006-10-14 12:08:59 · answer #4 · answered by gregory_s19 3 · 2⤊ 0⤋
Biology
2016-03-28 09:08:34 · answer #5 · answered by Anonymous · 0⤊ 0⤋
After 28 years, one half remains
After 56 years, one quarter remains
After 112 years, one eighth remains or 0.125 mg.
2006-10-14 11:47:34 · answer #6 · answered by Auriga 5 · 1⤊ 2⤋
i looked at the other answers ,i,d say around .25 give or take a .
2006-10-18 03:56:21 · answer #7 · answered by internetsurferbrowser 1 · 0⤊ 1⤋
Thank you teachers in the answer forum.... I feel less stupid now
2006-10-14 11:54:33 · answer #8 · answered by Anonymous · 1⤊ 0⤋
uummm that's scary that the nuclear science got it wrong is the any hope for man.
2006-10-14 12:20:34 · answer #9 · answered by Anonymous · 0⤊ 1⤋
not me..
2006-10-14 11:48:31 · answer #10 · answered by babyyocca 5 · 0⤊ 1⤋