A polar covalent bond occurs between atoms of different electronegativities.
Polar covalent bonds occur one when one atom is more electronegative than the other.
Two or more atoms share electrons because Co= share
it can't be two metal atoms form a bood cause they are not sharing.
between a metal and a nonmetal
Nonmetals
Why does group 4A elements tend to form covalent bonds rather than ionic bonds? 
The difference in electronegativity determines the type of chemical bonding between atoms. Metals and nonmetals often have a large difference in electronegativity, and tend to form ionic bonds, while nonmetals bonded to nonmetals tend to have smaller electronegativities and tend to form covalent bonds.
Tellurium is an element and will tend to form ionic bonds but can also form covalent bonds. Any element on its own is always nonpolar.
Covalent bonds involve sharing of electrons.
It is used to form molecules and various compounds. In fact, most of the bonds are covalent bonds.
Why does group 4A elements tend to form covalent bonds rather than ionic bonds? 
Carbon will almost always form bonds with other carbon atoms, and that is part of what makes it such a useful element.
A metal bonding with non-metals tend to form ionic bonds, a non-metal that bonds with another non-metal tend to form covalent bonds.
Carbons almost always form covalent bonds.
Nonmetals form covalent bonds.
Non-metal+Non-metal
They all tend to form multiple covalent bonds.
Nitrogen and phosphorous will tend to form covalent bonds with each other.
The difference in electronegativity determines the type of chemical bonding between atoms. Metals and nonmetals often have a large difference in electronegativity, and tend to form ionic bonds, while nonmetals bonded to nonmetals tend to have smaller electronegativities and tend to form covalent bonds.
Tellurium is an element and will tend to form ionic bonds but can also form covalent bonds. Any element on its own is always nonpolar.
Covalent bonds involve sharing of electrons.
It is used to form molecules and various compounds. In fact, most of the bonds are covalent bonds.