The explanation is the effect of ionizing radiation on tissues and materials.
Three uses are:
- sterilizing of instruments and parapharmaceutic items
- diagnostic with radioactive isotopes (scintigraphy)
- treatment of cancers with radioactive isotopes
No. At least no more than any other rocks. Almost all materials contain some trace of radioactive material.
Generally, the smaller the nucleus, the less radioactive.
Not all of the transition elements are radioactive. Many of them are, and some of them have common radioactive isotopes, but some of them have no naturally occurring radioactive isotopes. Please note that all elements have synthetic radioactive isotopes, at least.
Least Common Denominator
Yes, at least theoretically
Radon is a noble gas and is radioactive. All of the other noble gasses have at least some synthetic radioactive isotopes. Radioactive isotopes of both krypton and argon exist in nature in trace quantities.
If you had a stable element 115, then by definition there would need to be at least one non-radioactive isotope. Stable elements are those that have at least one nonradioactive isotope. Of course, the other isotopes of the element could all be radioactive.
Gas
Gamma Beta Alpha
Typically, popcorn has no nutritional value. At least this is what i have been told from a medical university.Typically, popcorn has no nutritional value. At least this is what i have been told from a medical university.Typically, popcorn has no nutritional value. At least this is what i have been told from a medical university.Typically, popcorn has no nutritional value. At least this is what i have been told from a medical university.Typically, popcorn has no nutritional value. At least this is what i have been told from a medical university.Typically, popcorn has no nutritional value. At least this is what i have been told from a medical university.
There's no "scientific explanation" for that, at least partly because it doesn't happen.
Plutonium is a very toxic element; also is a radioactive element.