Half life is pretty much self explanatory in that after they go through 1 half life half of the radioactive decay remains.
1/2 x 1/2 x 1/2 = 1/8 = 0.125 = 12.5%
or you can divide 100% by 2, 3 times and you'll get 12.5%
After every half-life, 1/2 of the previous amount is left over. So:
After one half-life, 50%, or one-half of a radioactive element will be left.
Every half-life passed will lower the number of remaining atoms by 50%. So after 2 half-lives only 25% will remain.
After 7 half-lives only 0.78% remains.
After 3 half-lives, (1/2 x 1/2 x 1/2) = 1/8 remains. That's 12.5% .
After 6 half lives, the remaining will be (1/2)6 i.e 1/64 th of the initial amount.
Hence by percentage it would be 1.5625 %
That's (1/2) to the power 6. Actually, that's the answer as a fraction; to convert that to a percentage, you multiply it by 100.
.195
0.78%
How much is left? 2.5 x ((0.5)((2009-1960)/28)) (A bit more than 25%)
In general, the elements with higher atomic numbers are the most radioactive and they are found at the bottom of the Periodic Table of Elements
Nickel is placed on the left of copper.
periods move from left to right find the element you are looking for and move all the way to the left if it is the third element down it is in period 3
the more metallic element will be the one below in group # or the one closer to the left in the period( the more metallic will be the one closer to the bottom left corner) since they have the lowest ionization energy and lower electronegativity
the halflife is 10 days
12.5%
12.5%
12.5%
That depends on the "half-life" of that particular radioactive element, which the question forgot to state. They're all different. Various radioactive elements have half-lives ranging from microseconds to millions of years.
First, it isn't very accurate to talk about a radioactive "element"; you should talk about radioactive isotopes. Different isotopes of the same element can have very different behavior in this sense. For example, hydrogen-1 and hydrogen-2 are stable, while hydrogen-3 is not (half-life about 19 years).Individual atoms, in a radioactive isotope, will decay at a random moment. The half-life refers to how long it takes for half of the atoms in a given sample to decay (and convert to some other type of isotope).
The half life is the time it takes for half the atoms in a given sample to decompose. Knowing this then after 27 days there is half the amount left. After 54 days then there is half that half left so that's a quarter.
How much is left? 2.5 x ((0.5)((2009-1960)/28)) (A bit more than 25%)
It disintegrates into its daughter nuclei that are much more stabler than the radioactive nuclei. If a sample of radioacictive material is left it will decay into another element over a period of time. Note that complete decay is not possible. A fraction of the original radioactive material will always remain in the sample.
12.5%
Radioactive dating is carried out with substances which were formed at some unknown point in the past and contained a known proportion of a radioactive isotope of some element. Radioisotopes decay into other elements at a fixed and known rate. So, if you know how much of the radioactive isotope is still left in the sample, then you can work out how long it would have taken for the rest to have decayed into other elements. That gives the age of the sample.
Truw