Question: what alkaline earth metals is radioactive?
Answer: Radioactivity. All of the alkaline earth metals, except magnesium and strontium, have at least one naturally occurring radioisotope: beryllium-7, beryllium-10, and calcium-41 are trace radioisotopes. Calcium-48 and barium-130 have very long half-lives and thus occur naturally. All isotopes of radium are radioactive.