Answer:
An atom with 1 valence electron and an atom with 7 valence electrons
Step-by-step explanation:
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.
For example:
In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive.
the number of valance electrons of oxygen are six and hydrogen is one that's why two hydrogen atoms are attached with one oxygen atom and complete the octet.