Compounds are polar when the shared electron moves towards the atom with the greater mass. The atom towards which the electron shifts get a S- (slight negative charge) while the other atom contains a S+ (slight positive charge). The polar covalent molecule has two centers of charge and this is known as "dipole". There is great difference in the electronegativity of the atoms. If it were non-polar the electronegativity difference would be zero.
For a polar molecule is a molecule in which the centroid of the positive charges are different from the centroid of the negative charges. It can also be described as an asymmetric molecule with non-uniformpositive and negative charges. Also called dipole. A polar molecule had a partial positive charge in one part of the molecule and a complementary negative charge in another part. A water molecule is an example of a water molecule (H2O). A water molecule is polar because its O-H bonds are VERY polar, and its bent geometric shape makes the distribution of those polar bonds asymmetrical. The side of the water molecule containing the more electronegative oxygen atom is partially negative, and the side of the molecule containing the less electronegative hydrogen atoms is partially positive.
The difference between covalent bonds/molecules and ionic bonds/molecules is that in an ionic bond, the atoms are bound together by the attraction oppositely- charged ions. For example, sodium and chloride form an ionic bond, to make NaCl, or table salt. In a covalent bond, the atoms are bound by shared electrons.
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Describe a Beta particle.
A fast-moving electron emitted by radioactive decay of substances. (The emission of beta particles was originally regarded as a ray.)
