0It may be note that a covalent bond is not only formed between two similar atoms, but it may be formed between dissimilar atoms also. For example, hydrogen and chlorine form a covalent bond between their atoms. In HCI, hydrogen atom (1) has only one electron in its valence shell and chlorine atom (2,8,7) has seven electrons in its valence shell. Therefore, by mutual sharing of electron pair between hydrogen and a chlorine atom. Both the atoms acquit nearest noble gas configuration.
