Chemistry

This is a Multiple Choice Questions as classified in NCERT Exemplar

option (ii)& (iii)

Isoelectronic species/ions are those species that possess the same number of electrons.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (i), (iii)& (iv)

He with 1s² electronic configuration has the highest electron gain enthalpy in the periodic table. In any period the alkali metals have the lowest effective nuclear charge in that particular period for which its atomic radius is the highest in that period.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (i)& (iv)

Both S and Cl have the higher tendency to gain electrons in order to attain stable the nearest noble gas configuration i.e. of Argon.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option   (i)& (iv)

The s-block elements and p-block elements together are called representative elements.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (i) & (iii)

Alkali metals and alkaline earth metals have low ionization enthalpy.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (ii) & (iii)

Both P and S have vacant d-orbital for which they execute extended covalency.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (i)

The electron gain enthalpy of 2p orbital is higher than that of the 3s orbital

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (iii) d-block

Lanthanum is the element with the atomic number 57 and it belongs to the d-block.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (iii)

High amount of energy has to be supplied in order to overcome the e^- - e ^- repulsion that arises when O^- gets converted to O^2- by accepting an electron

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (iv)

I⁺ possess the highest effective nuclear charge whereas I^- possess the least among the given species.