Question

Sodium chloride or table salt is a compound formed when sodium loses its valence electron to chlorine. Which type of bond formation takes place in sodium chloride? A. Covalent bond B. Ionic bond C. Metallic bond

Answer 1

Sodium chloride is an ionic bond.

Sodium (Na) only has one valence electron.

So, when it gives its valence electron away to Chlorine, it has none left.

That's how we know that it's an ionic bond.
Sodium gives all of its valence electrons to Chlorine.
They're not sharing any electrons.

Answer 2

You can do this question by the process of elimination. It's really easy when you use the periodic table. There is a stair case looking thing on there which shows you what are metals and what are non metals. Covalent bonds are bonds between 2 non-metallic substances.
Ionic bonds are between one metal and one non metal.
Metallic bonds are obviously bonds between two metals.
Chlorine is a non-metal where as sodium is a metal, hence ionic bond.