The bond between calcium (Ca) and fluorine (F) would be considered ionic.
To understand why, we need to look at the properties of the two elements involved. Calcium is a metal and belongs to group 2 of the periodic table, which means it tends to lose two electrons to achieve a stable electronic configuration. On the other hand, fluorine is a non-metal and is highly electronegative, meaning it has a strong tendency to attract electrons.
When calcium and fluorine bond, calcium donates its two valence electrons to two fluorine atoms. This transfer of electrons from calcium to fluorine results in the formation of positively charged calcium ions (Ca2+) and negatively charged fluoride ions (F–). The electrostatic attraction between these oppositely charged ions creates an ionic bond.
In contrast, pure covalent bonds occur between two non-metals that share electrons equally, while polar covalent bonds happen between two different non-metals that share electrons unequally due to differences in electronegativity. Since we have a metal (calcium) and a non-metal (fluorine), and since there is a complete transfer of electrons rather than sharing, the bond is classified as ionic.