Problem 55 - A Complete Resource Book in Chemistry for JEE Main

Question

Number of electrons shared in the formation of nitrogen molecule is (a) 10 (b) 8 (c) 6 (d) 2

Step-by-Step Solution

Answer

6 electrons are shared in a nitrogen molecule.

Step 1: Understanding Molecular Formation

To determine the number of electrons shared in the formation of a nitrogen molecule, we need to examine how nitrogen atoms form a N₂ molecule. Nitrogen atoms are represented by the symbol 'N' and have 5 electrons in their outer shell, needing 3 more electrons to achieve a stable configuration.

Step 2: Visualizing Electron Sharing

In the N₂ molecule, two nitrogen atoms come together to share electrons to achieve stability. Each nitrogen atom needs 3 electrons and shares 3 of its own, leading to a total sharing of 6 electrons between the two nitrogen atoms.

Step 3: Calculating the Total Shared Electrons

Since each nitrogen atom shares 3 electrons, for two nitrogen atoms in total, they share 3 + 3 = 6 electrons to form the triple bond in the nitrogen molecule (N≡N). This triple bond consists of three pairs (or 6 electrons) being shared.

Key Concepts

Nitrogen Molecule

The nitrogen molecule, often represented as N₂, is a diatomic molecule meaning that it consists of two nitrogen atoms bonded together. Nitrogen is an essential element that makes up about 78% of Earth's atmosphere. In order for these two nitrogen atoms to come together and form a stable molecule, they share electrons in a way that both atoms gain a full outer shell of electrons. This molecular formation ensures stability and is a key concept in understanding how nitrogen molecules are structured.

Electron Sharing

Electron sharing is a fundamental aspect of chemical bonding, particularly in covalent bonds. It involves atoms coming together to share electrons so that each can achieve a complete outer electron shell, similar to the nearest noble gas configuration.

• For a nitrogen molecule (N₂), each nitrogen atom has five valence electrons and needs three more to become stable.
• By sharing three of their own electrons with another nitrogen atom, each achieves this full outer shell.

This mutual exchange of electrons not only stabilizes the individual nitrogen atoms but also holds them together in the molecule.

Triple Bond

A triple bond is a type of chemical bond where three pairs of electrons are shared between two atoms. In a nitrogen molecule, the two nitrogen atoms share a total of six electrons in the form of three pairs. This is represented by the symbol N≡N, where each line between the letter 'N' indicates a pair of shared electrons.

• This triple bonding is one of the strongest types of covalent bonds.
• It contributes to the high stability and inertness of the nitrogen molecule.

The strength of the triple bond is crucial as it requires a significant amount of energy to break, making nitrogen gas less reactive under normal conditions.

Molecular Formation

The process of molecular formation involves the sharing or exchange of electrons between atoms. This occurs so as to achieve a stable electronic arrangement. In the case of the nitrogen molecule, the formation begins with two nitrogen atoms approaching each other.

• Initially, these atoms are separate and unstable due to their incomplete outer electron shells.
• By sharing electrons, the atoms effectively "lock" together in a stable structure through covalent bonding.

This sharing and locking process is an essential principle of molecular chemistry and is crucial for the formation of many different compounds and elements in nature.