Radioactive isotopes???

Question

Would you expect an isotope with a long half-life to be more, the same, or less radioactive than an isotope with a short half-life? Explain.

Answer 1

Less radioactive.

Suppose X has a half-life of 10 days, Y has a half-life of 5 days, and we have 10 g of each. At the end of 10 days, 5g of X has decayed away, but 7.5g of Y has decayed. If atomic weights are about the same, then 50% more atoms of Y have decayed than of X. Radioactivity is nuclear decay, and the faster the decay the more intense the radioactivity.

Answer 2

Radioactive materials send out dangerous, radioactive particles when the decay.

An isotope with a long half-life takes a long time to decay, and so will radiate fewer particles, and will be less radioactive.

An isotope with a short half-life takes only a short time to decay, and so will radiate many more particles, and will be much more radioactive.

Hope that helps!