Answer:
1) The number of the listed compounds that have ionic bonds between them are 5 compounds
2) Their formulas showing their charges within the compounds are;
NaCl ↔ Na⁺+Cl⁻
MgO ↔ Mg²⁺+O²⁻
K₂O ↔ 2K⁺+O²⁻
LiF ↔Li⁺+F⁻
CaO ↔ Ca⁺+O²⁻
3) The major reason they were selected is because they are compounds formed by the combination of a metal and a nonmetal
Step-by-step explanation:
1) An ionic bond involves the transfer of an atoms valence to another atom, such that the ions formed by the ionic chemical bond will be oppositely charged
Therefore, metals, which are elements that mainly have a few electrons in their outermost shell, loses their valence electrons and become positively charged, while non metals, which require a few electrons to complete the stable octet electronic configuration, receive the electrons from the metallic atoms and become negatively charged
Therefore, the compounds formed between a metal and a nonmetal in the list are the the compounds containing ionic bonds, including
NaCl, MgO, K₂O, LiF, and CaO
Therefore, 5 compounds contain ionic bonds between them;
2) Their formulas are;
NaCl, MgO, K₂O, LiF, and CaO
3) The major reason that the chosen compounds contain ionic bonding between them is because they involve the combination of a metal and a nonmetal as follows;
a) NaCl → Na⁺ (metal ion) + Cl⁻(nonmetal ion)
b) MgO → Mg²⁺ (metal ion) + O²⁻(nonmetal ion)
c) K₂O → 2K⁺ (metal ion) + O²⁻(nonmetal ion)
d) LiF → Li⁺ (metal ion) + F⁻(nonmetal ion)
e) CaO → Ca⁺ (metal ion) + O²⁻(nonmetal ion)