In the modern periodic table, the period indicates the value of:

A. atomic number

B. atomic mass

C. principal quantum number

D. azimuthal quantum number.

The first (∆_iH₁) and the second(∆_iH₂) ionization enthalpies (in kJ mol^–1) and the electron gain enthalpy (in kJ mol^–1) of a few elements are given below:

Which of the above elements is likely to be?

A. the least reactive element.

B. the most reactive metal.

C. the most reactive non-metal.

D. the least reactive non-metal.

E. the metal which can form a stable binary halide of the formula MX₂(X=halogen).

F. the metal which can form a predominantly stable covalent halide of the formula MX (X=halogen)?

Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements.

A. Lithium and oxygen

B. Magnesium and nitrogen

C. Aluminium and iodine

D. Silicon and oxygen

E. Phosphorus and fluorine

F. Element 71 and fluorine

Which of the following statements related to the modern periodic table is incorrect?

A. The p-block has 6 columns, because a maximum of 6 electrons can occupy all the orbitals in a p-shell.

B. The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.

C. Each block contains a number of columns equal to the number of electrons that can occupy that subshell.

D. The block indicates value of azimuthal quantum number (l) for the last subshell that received electrons in building up the electronic configuration.

Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?

(a) Valence principal quantum number (n)

(b) Nuclear charge (Z)

(c) Nuclear mass

(d) Number of core electrons.