Give alongside is a part of the periodic table :
As we move horizontally from left to right:

Li	Be		B	C	N	O	F
Na	Mg		Al	Si	P	S	Cl

(i) What happens to the metallic character of the elements?
(ii) What happens to the atomic size?

Q.

Given alongside is a part of the periodic table :

$\begin{array}{cccccccc}Li& Be& & B& C& N& O& F\\ Na& Mg& & Al& Si& P& S& Cl\end{array}$

As we move horizontally from left to right :

(i) What happens to the metallic character of the elements ?

(ii) What happens to the atomic size ?

Q. (a) What are the periods and groups in a periodic table? Give two characteristics of each.
(b) In terms of electronic configurations, explain the variation in the size of the atoms of the elements belonging to the same period and same group.
(c) Given alongside is a part of the periodic table. As we move vertically downward from Li to Fr:

Li	Be
Na
K
Rb
Cs
Fr	Ra

(i) What happens to the size of atoms?
(ii) What happens to their metallic character?
(d) Name two properties of elements whose magnitudes change when going from top to bottom in a group of the periodic table. In what manner do they change?
(e) Rewrite the following statement after correction, if necessary:
Groups have elements with consecutive atomic numbers.

Q.

Given below are a few elements arranged in the order of increasing atomic masses.
Identify the pair of elements with similar properties according to Newlands’ Law of Octaves.

Q. State whether the following elements belong to a Group (G), Period (P) or Neither Group nor Period (N).

Elements	G/P/N
$Li,C,O$
$Mg,Ca,Ba$
$Br,Cl,F$
$C,S,Br$
$Al,Si,Cl$
$Li,Na,K$
$C,N,O$
$K,Ca,Br$

Q.

Complete the following table relating to the atomic structure of some elements.

$\begin{array}{cccccc}\text{Element}& \text{Atomic}& \text{Mass}& \text{Number of}& \text{Number of}& \text{Number of}\\ \text{Symbol}& \text{Number}& \text{Number}& \text{Neutrons}& \text{Electrons}& \text{Protons}\\ Li& 3& 6& & & \\ Cl& 17& & 20& & \\ Na& & & 12& & 11\\ Al& & 27& & & 13\\ S& & 32& 16& & \end{array}$