As you move down a group, the atomic radius gets LARGER, so atoms have a weaker hold on their electrons and are less reactive. Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital.

Electronegativity is the measure of the ability of an atom in a bond to attract electrons to itself. Electronegativity increases across a period and decreases down a group. Down a group, the number of energy levels (n) increases, and so does the distance between the nucleus and the outermost orbital.

On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you move down a group.

The positively charged protons in the nucleus attract the negatively charged electrons. As the number of protons in the nucleus increases, the electronegativity or attraction will increase. Therefore electronegativity increases from left to right in a row in the periodic table.

Atomic radius increases as we move from top to bottom in a group of the periodic table because a new shellof electrons are added to the atoms at every step. As the size of the atoms increases which leads to an increase in atomic radius of an atom.

Metal has the ability to lose an electron. When an electron is added then the size of atom goes decreasing due to nuclear pull which ultimately makes metals difficult to lose electrons. Hence metallic character decreases while going from left to right in a period.

The third period contains only eight elements even though the electron capacity of the third shell is 18 because when the other shells get filled and the resultant number of electrons becomes eighteen, it gets added up and settles in the third electron shell and three shells are acquired by the fourth period.

Metallic character increases down a group due to increase in atomic size. Thus, the outermost electrons are farther away from the nucleus and therefore can be lost easily. Hence, the electropositive character or metallic character increases.

Boron

Group 14 is the carbon family. The five members are carbon, silicon, germanium, tin, and lead. All of these elements have four electrons in their outermost energy level. Of the Group 14 elements, only carbon and silicon form bonds as nonmetals (sharing electrons covalently).

The nitrogen family includes the following compounds: nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). All Group 15 elements have the electron configuration ns2np3 in their outer shell, where n is equal to the principal quantum number.