The 1st, 2nd and 3rd ionisation enthalpies, I₁, I₂ and I₃, of four atoms with atomic numbers n, n + 1, n + 2, and n + 3, where n < 10, are tabulated below. What is the value of n?

Among the following, the number of elements showing only one non-zero oxidation state is :
O, Cl, F, N, P, Sn, Tl, Na, Ti

Identify the correct order of acidic strengths of CO₂, CuO, CaO, H₂O

Identify the least stable ion amongst the following

Read the following statement and explanation and answer as per the options given below

ASSERTION : The first ionization energy of Be is greater than that of B.

REASON : 2p orbital is lower in energy than 2s.

The correct order of acidic strength is

Amongst H₂O, H₂S, H₂Se and H₂Te, the one with the highest boiling point is

The correct order of radii is

Which of the following has the maximum number of unpaired electrons?

Which has most stable +2 oxidation state?

The statement that is not correct for the periodic classification of element is

Amongst the following elements (whose electronic configuration are given below), the one having the highest ionization energy is:

Which one of the following is the strongest base?

Which one of the following is the smallest in size?

The first ionisation potential of Na, Mg, Al and Si are in the order

The first ionisation potential in electron volts of nitrogen and oxygen atoms are respectively given by

Atomic radii of fluorine and neon in Angstrom units are respectively given by

The electronegativity of the following elements increases in the order

The element with the highest first ionization potential is

The correct order of second ionisation potential of carbon, nitrogen, oxygen and fluorine is

Ionic radii of

Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because

The statements that are true for the long form of the periodic table are:

The basic nature of the hydroxides of group 13 (Gr. III B) decreases progressively down the group.

The decreasing order of electron affinity of F, Cl, Br is F > Cl > Br

In group IA, of alkali metals, the ionisation potential decreases on moving down the group. Therefore, lithium is a strongest reducing agent

Arrange of the following in :
Increasing order of ionic size:
N^3-, Na⁺, F^-, O^2-, Mg²⁺

Arrange of the following in :
Increasing order of basic character
MgO, SrO, K₂O, NiO, Cs₂O

Arrange of the following in :
Arrange the following ions in order of their increasing radii:
Li⁺, Mg²⁺, K⁺, Al³⁺

Arrange the following in:
Increasing size:
Cl^-, S^2-, Ca²⁺, Ar

Arrange the following in:
Increasing acidic property:
ZnO, Na₂O₂, P₂O₅, MgO

Arrange the following in:
Decreasing ionic size:
Mg²⁺, O^2-, Na⁺, F^-

Arrange the following in:
Increasing first ionisation potential :
Mg, Al, Si, Na

On Mulliken scale, the average of ionization potential and electron affinity is known as _____.

The energy released when an electron is added to a neutral gaseous atom is called ______ of the atom.