…A… are formed when atoms of different elements combine in a …B… ratio. Here, A and B refer to — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question

💡 Solution & Explanation

# Solution The question asks what is formed when atoms of different elements combine in a specific ratio, and what that ratio is called. **Step 1: Identify what forms when different elements combine** When atoms of different elements chemically combine, they form **compounds**. **Step 2: Identify the ratio term** The ratio in which atoms combine is called a **simple whole number ratio** (or fixed ratio). **Step 3: Complete the statement** - **A = Compounds** (substances formed from two or more elements) - **B = Simple whole number ratio** (the fixed proportion in which atoms combine) **Why A is correct:** Compounds are defined as substances composed of two or more elements chemically bonded in a definite proportion by mass. This is a fundamental concept in chemistry—compounds always have a fixed composition and are formed when different elements unite. **Key principle:** This relates to the Law of Definite Proportions, which states that a compound always contains the same elements in the same proportion by mass.