Classification of Elements

Which among the following elements is not a representative element?

Which of the following processes is endothermic?

How to study the classification of elements and periodicity in properties?

What is meant by periodicity in the properties of elements?

Why is the Classification of Elements Necessary?

In which of the following pairs, the outer most electronic configuration will be the same?

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.

Assertion (A) : The first ionization enthalpy for oxygen is lower than that of nitrogen

Reason (R) : The four electrons in 2p orbitals of oxygen experience more electron electorn repulsion.

In the light of the above statements, choose the correct answer from the options given below:

Consider the following orders given below.

(i) S > Se > Te > O (Electron Affinity)

(ii) $N^{-3}>O^{2-}>F^{-}>N{a}^{+}>M{g}^{2+}$  (Ionic Size)

(ii) Fe²⁺ > Fe³⁺ > Fe⁴⁺ (Ionization Enthalpy)

(iv) H < B < P < C < Cl (Electronegativity)

(v) Na⁺ < Mg²⁺ < Al³⁺ (Extent of hydration)

(vi) Li > Na > K > Rb > Cs (Reducing Nature)

(vii) LiF(s) > LiCl(s) > LiBr(s) (Lattice Energy)

If x = number of correct orders

y = number of incorrect orders

then the value of $\left(1+\frac{y}{x}\right)$  is.

If x = Group number of Europium (atomic number 63)

y = Period number of Americium (atomic number 95)

z = Most stable oxidation state shown by Gadolinium (atomic number 64)

The sum of “number off filled orbitals” and “number of vacant orbitals” upto valence shell of Fe is