Answer:
A unit of mass used to express atomic and molecular weights, equal to one-twelfth of the mass of an atom of carbon-12. It is equal to approximately 1.66 x 10-27 kg.
Explanation:
Answer: One formula unit of NaCl consists of one cation, whose chemical symbol is
and one anion whose chemical symbol is 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The cation is formed by the metal sodium which forms
and the anion is formed by non metal chlorine which forms
.
For a formula unit of sodium chloride, the charges have to be balanced , thus the valencies of ions are exchanged and the neutral compound result. Thus
and
combine to form neutral 
They will repel one another because opposites attract, but like charges will repel.
Answer: There are
atoms present in 0.500 mol of
.
Explanation:
According to the mole concept, there are
atoms present in 1 mole of a substance.
In a molecule of
there is only one carbon atom present. Therefore, number of carbon atoms present in 0.500 mol of
are as follows.

Thus, we can conclude that there are
atoms present in 0.500 mol of
.