Correct statement among the following regarding P, S, Cl, F is :

1.	F has most negative electron gain enthalpy, and S has least negative electron gain enthalpy.
2.	Cl has most negative electron gain enthalpy, and S has least negative electron gain enthalpy.
3.	Cl has most negative electron gain enthalpy, and P has least negative electron gain enthalpy.
4.	F has most negative electron gain enthalpy, and P has least negative electron gain enthalpy.

The formula of a compound that is formed by the Aluminium and Sulphur is:

The correct graph depicting ionization energies for 2^nd period elements is:

1.
2.
3.
4.	None of the above

Abnormally high ionization enthalpy of B as depicted in the graph below can be due to : 

1. Completely filled 2p subshell.

2. Completely filled 2s subshell.

3. Completely filled 3d subshell.

4. Completely filled 4f subshell.

The graph between ionization energy and atomic number for the first group elements is shown below:

The element represented by Y in the graph above is:

1. Cs 

2. Rb

3. Ca

4.  K

In the following graph of variation of ionization energy with atomic number, X, Y, and Z represent elements.

The group number of X, Y, and Z elements is:

Consider the following curves:

X represents group with highest atomic radius. The element that belongs to Y group can be : 

The correct order of ionization energy of W, X, Y and Z is-

Match the following isoelectronic species in Column I and Column II: 

The ionic radii vary in :

Choose the correct option :

1. (a), (c)

2. (b), (c)

3. (c), (d)

4. (b), (d)