Why does the s orbital fill before the p orbitals? A. The s orbital is lower in energy than the p orbital.
B. The s orbital holds fewer electrons than a p orbital.
C. The s orbital belongs to a different energy level than the p orbital.
D. The s orbital is higher in energy than the p orbital.

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent