Which of the following molecules contains the fewest covalent bonds?
A.
Chlorine molecule
B.
Ammonia molecule
C.
Methane molecule
D.
Water molecule
The Correct Answer and Explanation is:
The correct answer is A. Chlorine molecule (Cl₂).
To understand why the chlorine molecule contains the fewest covalent bonds among the given options, we need to analyze the structure of each molecule:
- Chlorine molecule (Cl₂): This molecule consists of two chlorine atoms bonded together by a single covalent bond. In a Cl₂ molecule, each chlorine atom contributes one electron to form a pair, resulting in one covalent bond.
- Ammonia molecule (NH₃): Ammonia has one nitrogen atom and three hydrogen atoms. The nitrogen atom forms three covalent bonds: one with each of the three hydrogen atoms. Thus, NH₃ has a total of three covalent bonds.
- Methane molecule (CH₄): Methane consists of one carbon atom bonded to four hydrogen atoms. The carbon atom forms four covalent bonds, one with each hydrogen atom. Therefore, CH₄ has a total of four covalent bonds.
- Water molecule (H₂O): Water consists of one oxygen atom bonded to two hydrogen atoms. The oxygen atom forms two covalent bonds—one with each hydrogen atom. Thus, H₂O has a total of two covalent bonds.
Comparing the number of covalent bonds in each molecule:
- Cl₂: 1 bond
- NH₃: 3 bonds
- CH₄: 4 bonds
- H₂O: 2 bonds
Clearly, the chlorine molecule has only one covalent bond, which is fewer than any of the other molecules listed. This illustrates that while all these molecules involve covalent bonding, Cl₂ stands out due to its simplicity and lower number of bonds. In summary, the chlorine molecule contains the fewest covalent bonds among the options provided.