Question 1

Which of the following p-block elements has the highest electronegativity?

Accepted Answer

Fluorine is the most electronegative element on the periodic table with an electronegativity value of 4.0 on the Pauling scale.

Question 2

What is the electronic configuration of Boron (B), a p-block element?

Accepted Answer

Boron has atomic number 5 with configuration 1s² 2s² 2p¹, making it the first element in group 13 of the p-block.

Question 3

Which p-block element forms a diatomic molecule and exhibits allotropy with forms like white, red, and black phosphorus?

Accepted Answer

Phosphorus exhibits multiple allotropic forms including white (P₄), red, and black phosphorus due to different structural arrangements.

Question 4

In the p-block, which group contains elements that are generally non-metallic and form acidic oxides?

Accepted Answer

Group 15 (pnictogens: N, P, As, Sb, Bi) forms acidic oxides like N₂O₅ and P₂O₅ when combined with oxygen.

Question 5

Which of the following p-block elements is a noble gas with a complete octet configuration and zero electronegativity?

Accepted Answer

All noble gases (Ne, Ar, Kr, Xe, Rn) in group 18 have complete p-orbitals, full octets, and essentially zero electronegativity.

Question 6

Which of the following p-block elements has the highest electronegativity value?

Accepted Answer

Fluorine (F) is the most electronegative element in the periodic table with a value of 3.98 on the Pauling scale.

Question 7

The atomic radius of p-block elements decreases across a period. Which element has the smallest atomic radius in Period 3?

Accepted Answer

Argon (Ar), being the rightmost element in Period 3 with maximum effective nuclear charge, has the smallest atomic radius.

Question 8

Which of the following statements about boron is CORRECT?

Accepted Answer

Boron is a non-metal metalloid that primarily forms covalent compounds due to its small size and high ionization energy.

Question 9

In the nitrogen family (Group 15), which element exhibits allotropy with the most number of distinct forms?

Accepted Answer

Phosphorus exists in multiple allotropic forms including white, red, black, and violet phosphorus, more than any other Group 15 element.

Question 10

Which oxide of sulfur is used as a preservative and disinfectant in food and wine industries?

Accepted Answer

Sulfur dioxide (SO₂) is widely used as a preservative and disinfectant due to its antimicrobial properties.

Question 11

The oxidation state of chlorine in hypochlorous acid (HClO) is:

Accepted Answer

In HClO, oxygen has -2 and hydrogen has +1, so chlorine has oxidation state +1 to balance the molecule.

Question 12

Which of the following p-block elements forms the most stable hydride?

Accepted Answer

Water (H₂O) formed by oxygen is the most stable hydride among these elements due to oxygen's high electronegativity and small size.

Question 13

In the carbon family (Group 14), the tendency to show metallic character increases down the group. Which element in this group is a metalloid?

Accepted Answer

Silicon (Si) is classified as a metalloid with properties intermediate between metals and non-metals in Group 14.

Question 14

Which of the following p-block elements exhibits the property of catenation most extensively after carbon?

Accepted Answer

Silicon, like carbon, forms long chains and networks due to favorable Si-Si bond energy, making it the second most prominent catenating p-block element.

Question 15

The oxidation state of phosphorus in H₃PO₂ (hypophosphorous acid) is:

Accepted Answer

In H₃PO₂, the structure is HP(=O)OH where one P-H bond exists; solving for oxidation state: x + 3(+1) + 2(-2) = 0 gives x = +1.

Question 16

Among the halogens, which element has the highest electronegativity and the strongest tendency to form ionic compounds with metals?

Accepted Answer

Fluorine possesses the maximum electronegativity (4.0) of all elements and forms the strongest metal-halogen ionic bonds due to the highest electron affinity and smallest atomic radius.

AFCAT p-Block Elements

p-Block Elements — Practice Questions