Answer» Steps to write Lewis dot structures : - Add the total number of valence electrons of combining atoms in the molecule.
- In anions, add one electron for each negative charge.
- In cations, subtract one electron from valence electrons for each positive charge.
- Write skeletal structure of the molecule to show the atoms and number of valence electrons forming the single bond between the atoms.
- Add remaining electron pairs to complete the octet of each atom.
- If octet is not complete form multiple bonds between the atoms such that octet of each atom is complete.
- In polyatomic atoms and ions, the least electronegative atom is the central atom.
- e.g. In \(SO_4^{2-}\) ion, ‘S’ is the central atom and in \(NO^-_3\), ‘N’ is the central atom.
- After writing the number of electrons as shared pairs forming single bonds, the remaining electron pairs are used either for multiple bonds or they remain as lone pairs.
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