In typical covalent compounds such as ammonia and many organic molecules, how many covalent bonds does a neutral nitrogen atom usually form to complete its valence shell?

Introduction / Context:
This question examines basic valence concepts in covalent bonding, focusing on nitrogen. Knowing how many covalent bonds an atom typically forms is essential for drawing Lewis structures, understanding molecular shapes and predicting the formulas of simple inorganic and organic compounds that contain nitrogen.

Given Data / Assumptions:

• The atom of interest is a neutral nitrogen atom in its common valence state.
• We are asked how many covalent bonds it typically forms in ordinary molecules.
• We consider classic examples like ammonia, amines and many organic nitrogen compounds.
• We assume basic knowledge of electronic configuration and the octet rule.

Concept / Approach:
Nitrogen has atomic number 7 and an electronic configuration of 1s2 2s2 2p3. This means it has five valence electrons in the second shell. To achieve a stable octet (eight valence electrons), nitrogen usually shares three of its valence electrons in covalent bonds and retains one lone pair. This is seen in many common compounds such as ammonia (NH3), where nitrogen forms three N–H covalent bonds and has one lone pair of electrons.

Step-by-Step Solution:
1) Write the valence shell configuration of nitrogen: 2s2 2p3, giving a total of five valence electrons.2) According to the octet rule, atoms tend to achieve eight electrons in their outer shell for stability.3) Nitrogen already has five valence electrons, so it needs three more electrons to reach an octet.4) In covalent bonding, it can obtain these three additional electrons by forming three shared pairs (three covalent bonds) with other atoms such as hydrogen or carbon.5) After forming three covalent bonds, nitrogen has three bonding pairs and one lone pair, giving eight electrons around it and a typical valency of 3.

Verification / Alternative check:
Consider ammonia, NH3. Each hydrogen atom contributes one electron, and nitrogen contributes one electron to each of the three N–H bonds. This creates three shared pairs (three covalent bonds). Counting electrons around nitrogen: two from its lone pair plus six from three bonding pairs gives eight electrons, satisfying the octet rule. This same pattern appears in many amines and organic nitrogen compounds, confirming that three covalent bonds is the standard for neutral nitrogen in simple molecules.

Why Other Options Are Wrong:
2: Two covalent bonds would give nitrogen only seven electrons around it (four from bonds and three lone electrons), which is less common for a stable neutral nitrogen atom in simple molecules.
4: Nitrogen can appear as four coordinate in species such as ammonium ion (NH4+), but the fourth bond is a coordinate (dative) bond and the atom carries a positive charge, not a typical neutral covalent bonding pattern.
1: One covalent bond would leave nitrogen far from the octet and is not representative of common stable compounds.
5: Five covalent bonds around nitrogen would exceed the octet and is not typical for second period elements.

Common Pitfalls:
Some students confuse the usual three covalent bonds of neutral nitrogen with the four bonds seen in ammonium ion, forgetting that the latter involves a positive charge and a coordinate bond. Others assume that any group 15 element can routinely expand its octet like heavier elements, which is not true for nitrogen due to the absence of available d orbitals in the second period. Always think of nitrogen as having five valence electrons and needing three more to complete an octet, leading naturally to three standard covalent bonds.

Final Answer:
A neutral nitrogen atom in typical covalent compounds usually forms three covalent bonds to complete its valence shell.