Question

A substance that contains chemically similar atoms, and the atoms always exist in pairs. What is that substance called?

• A. Solution
• B. Element
• C. Compound
• D. Mixture

Hint:

Remember: \[ \boxed{ \begin{aligned} \text{Element} &\rightarrow \text{Only one type of atom}\\ \text{Compound} &\rightarrow \text{Two or more different atoms chemically combined}\\ \text{Mixture} &\rightarrow \text{Physical combination of substances} \end{aligned} } \] Many elemental gases exist as diatomic molecules such as \(H_2,\;N_2,\;O_2,\;Cl_2\).

Answer 1

The Correct Option is B

Concept: An

element is a pure substance made up of only one type of atom. Some elements exist as individual atoms (monoatomic), while others exist as molecules containing two identical atoms, known as diatomic molecules. Examples of diatomic elements are \[ \boxed{H_2,\;N_2,\;O_2,\;F_2,\;Cl_2,\;Br_2,\;I_2.} \] These molecules contain chemically identical atoms bonded together.

Step 1: Analyse the given statement.
The substance contains

• chemically similar atoms,

• atoms existing in pairs.
Thus, it consists of molecules such as \[ H_2,\;O_2,\;N_2, \] where both atoms are identical.

Step 2: Identify the type of substance.
Since only one kind of atom is present, the substance is classified as \[ \boxed{\text{An Element}.} \] It is not a compound because compounds contain atoms of different elements. It is also not a mixture or solution.

Step 3: Choose the correct option.
Hence, \[ \boxed{\textbf{Option (B)}} \] is the correct answer.