What does polar, nonpolar, covalent, nonpolar covalent, polar covalent mean?

Question

Please help me.

be more specific.

Answer 1

polar refers to bonds and molecules where the electrons tend to be closer to one atom than another because of the "strength" with which the atoms "pull" the electrons. This "strength" is usually measured by a number called "electronegativity". There should be a chart or list of these numbers in your text book.

"Covalent" is a type of chemical bond where the electrons are shared between atoms, rather than transferred (ionic bond). Usually covalent bonds form between two non-metals.

From your question it looks like the first two terms (polar and nonpolar) are referring to individual chemical bonds. Find the two atoms attached to either end of the bond, look up their electronegativities and see if one atom "pulls" on the electrons stronger than the other. This would produce a polar BOND.

The last two (nonpolar covalent; polar covalent) could refer to both a bond or a molecule. For the molecule you need polar bonds, and then you have to know the shape of the molecule since it is possible for the individual bond "pulls" to cancel each other - kind of like a tug of war. Generally if a molecule is symmetrical (triangle, tetrahedron or linear triatomic) the "pulls" cancel. Although the BONDS may be polar covalent, the entire MOLECULE would be nonpolar covalent.

Answer 2

When two homonuclear atoms having similar electrnegativity combines by covalent bonding the electrons are mutually shared by both the atoms . this is a non polar bond like H -H.N -N.When the combining atoms are different then the electrons are share unequally forming a + end (less e sharing)and - end(more e sharing) this type of bonding is called polar covalent. The mutual sharing of electrons by two or more than two atoms in order to attain the noble gas configuration and obey the octet rule is called covalency or covalent bonding. This concept was given by G.N. Lewis in 1916.

Answer 3

polar
1. Of or relating to a pole.
2. Having poles. Used of certain nerve cells having one or more processes.

nonpolar:
Molecule which has no separation of charge, so no positive or negative poles are formed.

for the rest of the definition check this site:
http://chemistry.about.com/library/glossary/bldef57380.htm

Answer 4

They are types of chemical bonds.