Answer:
If one element is a metal and the other element is a non metal
Explanation:
Ionic bonds are formed between metals and non metals. The nonmetal atom receives electron(s) from a metal atom to form an ionic substance. This means that ionic substances are basically an ion pair.
Covalent bonds are mostly formed between two nonmetals. These elements share electrons with each other in order to form the compound.
Answer:
Nitrogen accounts for 78% of the atmosphere, oxygen 21% and argon 0.9%. Gases like carbon dioxide, nitrous oxides, methane, and ozone are trace gases that account for about a tenth of one percent of the atmosphere.
Explanation:
