For the second period elements the correct increasing order of first ionisation enthalpy is:

1.  Li<Be<B<C<O<N<F<Ne

2.  Li<Be<B<C<N<O<F<Ne

3.  Li<B<Be<C<O<N<F<Ne

4.  Li<B<Be<C<N<O<F<Ne

Identify the INCORRECT match.

Electronic configuration of chalcogens in their outermost orbit is:

1. s² p³

2. s² p⁴

3. s² p⁵

4. s² p⁶

If IUPAC name of an element is "unununium" then correct statement regarding element is:

The element having electronic configuration [Kr]4d¹⁰4f¹⁴, 5s²5p⁶, 6s² belongs to:

1. s-block

2. p-block

3. d-block

4. f-block

One element has atomic weight 39. Its electronic configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹. The true statement for this element is: 

1. High value of IE                               

2. Transition element

3. Isotone with \(^{38}_{18} A r\)   $$

4. None of the above

The correctly matched option is:-

1. ${\mathrm{Fe}}^{+3}>{\mathrm{Fe}}^{+2}$ $>$ ${\mathrm{Fe}}^{+}$  : Order of atomic radius 

2. O > C > B > N   : Order of ionisation energy 

3. ${\mathrm{O}}^{-2}$ $<{\mathrm{O}}^{-}$ $<\mathrm{O}$ $<{\mathrm{O}}^{+}$ :  Increasing order of Z_eff

4. O < N < F < Ne  :  Order of electron affinity

The group of metals having the positive value of electron gain enthalpy is:

In terms of increasing non-metallic character, which of the following is the
correct order for the elements N, P, O, and S?

1. P < S < N < O

2. O < S < N < P 

3. O < N < S < P 

4. N < S < O < P

The most non-metallic element among the given elements is