Given below are the quantum numbers for 4 electrons. A. $$\mathrm{n}=3,l=2,{\mathrm{m}}_1=1,{\mathrm{m}}_{\mathrm{s}}=+1/2$$ B. $$\mathrm{n}=4,l=1,{\mathrm{m}}_1=0,{\mathrm{m}}_{\mathrm{s}}=+1/2$$ C. $$\mathrm{n}=4,l=2,{\mathrm{m}}_1=-2,{\mathrm{m}}_{\mathrm{s}}=-1/2$$ D. $$\mathrm{n}=3,l=1,{\mathrm{m}}_1=-1,{\mathrm{m}}_{\mathrm{s}}=+1/2$$ The correct order of increasing energy is :

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-electron repulsion. In the light of the above statements, choose the correct answer from the options given below.

Match List - I with List - II : .tg {border-collapse:collapse;border-spacing:0;} .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-c3ow{border-color:inherit;text-align:center;vertical-align:top} .tg .tg-0pky{border-color:inherit;text-align:left;vertical-align:top} List-I (Oxide) List-II (Nature) (A) $$C{l}_2{O}_7$$ (I) Amphoteric (B) $$N{a}_{2}O$$ (II) Basic (C) $$A{l}_2{O}_3$$ (III) Neutral (D) $$N_{2}O$$ (IV) Acidic Choose the correct answer from the options given below :

Among the following, basic oxide is :

Element "E" belongs to the period 4 and group 16 of the periodic table. The valence shell electron configuration of the element, which is just above "E" in the group is

The correct order of increasing ionic radii is

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The ionic radii of O2$$-$$ and Mg2+ are same. Reason (R) : Both O2$$-$$ and Mg2+ are isoelectronic species. In the light of the above statements, choose the correct answer from the options given below.

The correct order of electron gain enthalpies of Cl, F, Te and Po is

Given below are the oxides: Na2O, As2O3, N2O, NO and Cl2O7 Number of amphoteric oxides is :

The correct order of electron gain enthalpy ($$-$$ ve value) is :

The IUPAC nomenclature of an element with electronic configuration [Rn] $$5{\mathrm{f}}^{14}6{\mathrm{d}}^{1}7{\mathrm{s}}^2$$ is :

The first ionization enthalpies of Be, B, N and O follow the order

Given two statements below : Statement I : In $${\mathrm{Cl}}_2$$ molecule the covalent radius is double of the atomic radius of chlorine. Statement II : Radius of anionic species is always greater than their parent atomic radius. Choose the most appropriate answer from options given below :

The incorrect statement is

In which of the following pairs, electron gain enthalpies of constituent elements are nearly the same or identical? (A) Rb and Cs (B) Na and K (C) Ar and Kr (D) I and At Choose the correct answer from the options given below :

The first ionization enthalpy of Na, Mg and Si, respectively, are : 496, 737 and $$786\mathrm{kJ}{\mathrm{mol}}^{-1}$$. The first ionization enthalpy ($$\mathrm{kJ}{\mathrm{mol}}^{-1}$$) of $$\mathrm{Al}$$ is :

Which one of the following reactions indicates the reducing ability of hydrogen peroxide in basic medium?

Hydrogen has three isotopes : protium (1H), deuterium (2H or D) and tritium (3H or T). They have nearly same chemical properties but different physical properties. They differ in :

Dihydrogen reacts with CuO to give :

Consider the following reaction: $$2HS{O}_4^{-}(aq)\underset{(2)Hydrolysis}{\overset{(1)Electrolysis}{⟶}}2HS{O}_4^{-}+2H^{+}+A$$ The dihedral angle in product A in its solid phase at 110 K is :