What is a bond between a positive and negative ion called?
a) polar bond
b) ionic bond
c) covalent bond
d) metallic bond

Option (b) is the correct answer.

Explanation:

An ionic bond is defined as the bond formed due to transfer of electron(s) from one atom to another.  

An ionic bond will always be formed between a metal and a non-metal.

For example, sodium metal on donating its one valence electron to chlorine atom will lead to the formation of NaCl compound.

This is because an atom which loses its valence electrons (metals) acquires a positive charge and another atom which gains the electrons (non-metals) acquires a negative charge.  

Hence, these opposite charges strongly gets attracted towards each other forming a strong bond.

Whereas in a covalent bond, there will be sharing of electrons between the combining atoms.

For example, an molecule is formed due to sharing of electrons between the two oxygen atoms.

Thus, we can conclude that a bond between a positive and negative ion called an ionic bond.

astronomers such as edwin hubble.

answer is a

explanation: