Answer:
Its A i had hos question in usatestprep
Explanation:
Answer:
An atom is stable if the forces among the particles that makeup the nucleus are balanced. An atom is unstable (radioactive) if these forces are unbalanced; if the nucleus has an excess of internal energy. Instability of an atom's nucleus may result from an excess of either neutrons or protons.
Explanation:
Do you have a picture of the map?
Helium does not react with any other substances, thus the substance’s internal structure is never greatly affected and thus helium cannot have any chemical properties.