The elements of the second period of the periodic table are given below :

$\mathrm{Li}, \mathrm{Be}, \mathrm{B}, \mathrm{C}, \mathrm{N}, \mathrm{O}, \mathrm{F}$
(a) Give reasons to explain why atomic radius decreases from $\mathrm{Li}$ to $\mathrm{F}$.
(b) Identify the most (i) metallic and (ii) non-metallic element.

An element E has the following electronic configuration :

(a) To which group of the periodic table does element E belong?
(b) To which period of the periodic table does element E belong?
(c) State the number of valence electrons present in element E.
(d) State the valency of the element E.

Name two other elements which belong to the carbon family.

Name two other elements which belong to the sodium family.

Name two other elements which belong to the magnesium family.

Carbon $\left(\mathrm{Z}=6\right)$ and silicon $\left(\mathrm{Z}=14\right)$ are elements in the same group of the periodic table.

Give the electronic configuration of these atoms and state to which group and period these elements belong.

A part of the periodic table is shown below :

(a) Which of these is/are noble gases?
(b) Which of these have 3 valence electrons?
(c) Which of these have strong tendency to lose one electron?
(d) Which of these have good tendency to form monovalent anions?
(e) Which of these is/are alkaline earth metals?
(f) Which of these is metalloid?