Which of the following statements are correct regarding the Lewis dot structure while writing steps?.

The total number of electrons required for writing the structure are obtained by adding the valence electrons of the combining atoms

Knowing the chemical symbols of the combining atoms and having knowledge of the total skeletal structure of the compound, it is easy to distribute the number of electrons as bonding shared pairs between the atoms in proportions to the total bonds

In general the least electropositive atom occupies the central position in the molecule/ion

After accounting for the shared pairs of electrons for single bonds, the remaining electron pairs are either utilized for multiple bonding or remain as the lone pairs