Ncert Solutions Chemistry Class 11th

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.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (iii)

The lanthanoids which belong to the f-block elements are the elements where 4forbitals are filled progressively.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (iii)

Period number indicates the maximum value of principal quantum number

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (i)

The electron gain enthalpy decreases down the group, however as the size of F atom is much smaller thus it leads to repulsion upon addition of electrons on its 2p orbital for this electron gain enthalpy of Cl is higher than that of F.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (iii)

As per Aufbau principle 3d orbitals are filled first than 4s as due to lower n value.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (iii)

Gadolinium is a lanthanoid which belongs to the f-block elements with electronic configuration (n-2)f¹⁴ (n-1)d⁰-¹ns²

This is a Multiple Choice Questions as classified in NCERT Exemplar

Option (i)

As Mg contains fully filled 3s orbital thus its ionisation is higher than that of Na and Al.