Question

which one of the following elements is most likely to form a 2+ ion? calcium carbon fluorine oxygen sodium

Explanation:

To determine which element forms a \(2+\) ion, we analyze each option:

• Calcium (\(Ca\)) is an alkaline earth metal (Group 2). Atoms in Group 2 have 2 valence electrons, which they lose to achieve a stable octet, forming \(Ca^{2+}\).
• Sodium (\(Na\)) is in Group 1, loses 1 electron to form \(Na^+\).
• Fluorine (\(F\)) is in Group 17, gains 1 electron to form \(F^-\).
• Carbon (\(C\)) typically forms covalent bonds, not simple \(2+\) ions easily.
• Oxygen (\(O\)) gains 2 electrons to form \(O^{2-}\), not lose 2.

Answer:

A. calcium