Question

Atomicity of an element is:

• A. Valency of an element
• B. Atomic mass
• C. Number of atoms in one molecule of an element
• D. Isotope of an element

Hint:

The atomicity of an element indicates how many atoms of that element are bonded together in a molecule.

Answer 1

The Correct Option is C

• Option 1: Valency of an element - This is incorrect. The valency of an element refers to its ability to combine with other elements, typically based on the number of electrons in its outer shell. Atomicity is a different concept, relating to the number of atoms in a molecule of an element. 
• Option 2: Atomic mass - This is incorrect. The atomic mass refers to the mass of an atom, usually measured in atomic mass units (amu). Atomicity, on the other hand, refers to the number of atoms in one molecule of an element, not its mass.
• Option 3: Number of atoms in one molecule of an element - This is the correct answer. The atomicity of an element refers to the number of atoms that make up a single molecule of that element. For example, the atomicity of oxygen (O₂) is 2, as it consists of two oxygen atoms per molecule.
• Option 4: Isotope of an element - This is incorrect. An isotope refers to different forms of the same element that have the same number of protons but different numbers of neutrons. It is unrelated to the concept of atomicity, which deals with the number of atoms in a molecule.

Explanation:

The atomicity of an element refers to the number of atoms that make up a single molecule of that element. For example, oxygen (O₂) has an atomicity of 2 because each molecule of oxygen consists of two oxygen atoms. The atomicity helps define the molecular structure of elements, whether they exist as diatomic molecules (like O₂), tetraatomic molecules (like phosphorus, P₄), or monatomic molecules (like noble gases such as neon, Ne).