Which type of bonding involves the complete transfer of a valence electron from a less electronegative atom to a more electronegative one?

Ionic or electrovalent bonds

Explanation:

Ionic or electrovalent bonds are interatomic or intramolecular bonds which are formed between two kinds of atoms having a large electronegativity difference usually 2.1.

Electronegativity is the property that combines the ability of an atom to gain or lose electrons. It is expressed as the tendency with which atoms of elements attracts valence electrons in a chemical bond.

In this bond type, a metal transfers its electrons to a more electronegative atom which is a non-metal.

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg