Radioactive isotopes of an atom are a/ more stable b/ less stable c/ more abundant d/ more scarce

b/ less stable

Explanation:

Many elements that have one or more isotopes which are radioactive in nature have the nucleus which remains in an unstable state. The unstable nucleus breaks down, decay and emit the radiation. The nucleus in the atoms of these elements are unstable because it consists of unstable ratio of protons to neutron.

true

explanation:

who knows

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.