NDA General Ability Question (2025) — Solution

Step-by-step solution

A compound is a pure substance because it consists of molecules of only one kind, which are formed by the chemical combination of two or more elements in a fixed ratio by mass. The properties of a compound are entirely different from those of its constituent elements. The constituents of a compound cannot be separated by physical methods but can be separated by chemical or electrochemical methods. Therefore, the statement that a compound is an impure substance is incorrect. Answer: A compound is an impure substance