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Half of the radioactive atoms in a sample of sodium-24 will decay in 15 hours fifteen hours is the what of sodium-24?
Wiki User
∙ 14y ago
By definition, halflife is the time during which half of the atoms originally present will undergo radioactive change. Therefore, after 15 hours, the number of atoms of Na24 remaining will be half the original number, 500; after an additional 15 hours, the number of atoms remaining will be 250, and after 45 hours the number remaining will be 125 (this is the answer). (Actually, 1000 atoms is too small a number for the halflife to be exactly manifested, but the earlier part of the answer assumes that it is.)
so what he's trying to say is the answer is 125
Wiki User
∙ 8y ago
Colton Lynn
Wiki User
∙ 14y agoThat is known as the sodium-24 "half life"
Let's say there are 1000 radioactive atoms in a sample of sodium-24.
In 15 hours there will only be 500.
In 15 more hours there will only be 250, and so on.
Wiki User
∙ 12y agoBy simple inspection, you can see that four half-lives will occur for 93.755 % of the sample to decay. This is 6.245 % remaining, and the half-life progression is 0.5, 0.25, 0.125, and 0.0625, which is close to 0.06245.
The equation for half life is ...
AT = A0 2(-T/H)
... where A0 is the initial activity, AT is the activity after some time T, and H is the half-life in units of T.
Solving exactly for AT = 0.06245 and A0 = 1 (and H = 1, for now) ...
0.06245 = 2-T
log2(0.06245) = -T
T = 4.00115
... so, if H is 15 hours, then T is 60.0173 hours.
However, the half-life of sodium depends on the particular isotope. There are 20 different isotopes of sodium, one of which is stable. Of the remaining 19, one, 1124Na, has a half-life of 14.997 hours, decaying by beta- decay to 1224Mg, which is stable.
Wiki User
∙ 14y ago125
Wiki User
∙ 15y ago12.5 grams
Wiki User
∙ 13y ago1.125
Nesreen Rajab
0.63 g
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i got no idea
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This is its half-life.
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The half-life.
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It's called the half-life.
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Your question does not make sense. One sample of bohrium could have a certain amount of atoms, while another sample of bohrium may have a different number of atoms. You probably mean: How many protons does bohrium have? Although it is synthetic and radioactive, a bohrium atom can be retained for a few seconds. It then has 107 protons.
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After two half life it must be 1200 x 1/2 x 1/2 = 300 atoms.
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The length of time it takes for half of a radioactive sample to decay
