Classification of Elements and Periodicity

The 2s and the 2p orbital energies of hydrogen atom are $E_{2s}(\mathrm H)$ and $E_{2p}(\mathrm H)$, respectively. The 2s and the 2p orbital energies of lithium atom are $E_{2s}(\mathrm{Li})$ and $E_{2p}(\mathrm{Li})$, respectively. The correct option(s) about the orbital energies is(are)

The correct statement(s) regarding the periodic properties of elements is(are)

Given below are two statements :

Statement (I) : The first ionisation enthalpy of the elements Na, Mg, Cl and Ar follows the order Na > Mg > Cl > Ar.

Statement (II) : Among Ca, Al, Fe and B, the third ionisation enthalpy is very high for Ca.

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

The correct set that contains all kinds (basic, acidic, amphoteric and neutral) of oxides is :

Given below are two statements :

Statement I : The second ionization enthalpy of B, Al and Ga is in the order of B > Al > Ga.

Statement II : The correct order in terms of first ionization enthalpy is Si < Ge < Pb < Sn.

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

A monoatomic anion ($\ce{A-}$) has 45 neutrons and 36 electrons. Atomic mass, group in the periodic table and physical state at room temperature of the element (A) respectively are

The 1st ionization enthalpy for Mg is +737 kJ/mol. The most probable estimated value of the 2nd ionization enthalpy of Mg is ________.

The electronegativity of a group 13 element 'E' is same as that of Ge (on Pauling scale and upto one decimal point). The CORRECT statements about $\ce{E^{3+}}$ are

A. It can act as a reducing agent.

B. It can act as an oxidizing agent.

C. $\ce{E^{3+}}$ is more stable than $\ce{E+}$.

D. The standard electrode potential value for $\ce{E^{3+}}$/E is positive.

Choose the correct answer from the options given below:

Given below are two statements:

Statement I: The correct order of electronegativity of fluorine, oxygen and nitrogen is F > O > N.

Statement II: The oxidation state of oxygen in $\ce{OF2}$ is +2 and in $\ce{Na2O}$ is −2.

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

Given below are two statements :

Statement I: The number of pairs among $[\ce{Al2O3},\ \ce{Cr2O3}]$, $[\ce{Cl2O7},\ \ce{Mn2O7}]$, $[\ce{Na2O},\ \ce{V2O3}]$ and $[\ce{CO},\ \ce{N2O}]$ that contain oxides of same nature (acidic, basic, neutral or amphoteric) is 4.

Statement II: Among $\ce{Na2O}$, $\ce{Al2O3}$, CO and $\ce{Cl2O7}$, the most basic and acidic oxides are $\ce{Na2O}$ and $\ce{Cl2O7}$, respectively.

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

First and second ionization enthalpies of lithium are 520 kJ mol$^{-1}$ and 7297 kJ mol$^{-1}$ respectively. Energy required to convert 3.5 mg lithium (g) into $\ce{Li^2+}$(g) [$\ce{Li(g) -> Li^2+(g)}$] is ________ kJ mol$^{-1}$. (nearest integer)

[Molar mass of Li = 7 g mol$^{-1}$]

In a period, the first ionisation enthalpy of the element at extreme left and the negative electron gain enthalpy of the extreme right element, except noble gases, are respectively.

Match List - I with List - II.

Choose the correct answer from the options given below :

The pair(s) of diamagnetic ions is(are)

Given below are the oxides :

$\mathrm{Na_2O,\ As_2O_3,\ N_2O,\ NO}$ and $\mathrm{Cl_2O_7}$

Number of amphoteric oxides is :

Metals generally melt at very high temperature. Amongst the following, the metal with the highest melting point will be

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

Which of the following elements is considered as a metalloid?

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 $\mathrm{O^{2-}}$ and $\mathrm{Mg^{2+}}$ are same.

Reason (R) : Both $\mathrm{O^{2-}}$ and $\mathrm{Mg^{2+}}$ are isoelectronic species.

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

The correct order of increasing ionic radii is