‘amu’ has been replaced by ‘u’ which is known as …A… Here, A refers to — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question

💡 Solution & Explanation

# Understanding the Change from 'amu' to 'u' **Step 1: Identify what 'amu' stands for** - 'amu' = atomic mass unit (the old term) **Step 2: Recognize the modern replacement** - The SI unit that replaced 'amu' is the **unified atomic mass unit** - It is now denoted by the symbol **'u'** **Step 3: Understand the standardization** - This change occurred to provide a unified, internationally accepted standard - The unified atomic mass unit is defined relative to $^{12}C$ (carbon-12) atom - 1 u = $\frac{1}{12}$ of the mass of one $^{12}C$ atom **Step 4: Confirm the definition** - The term **'unified atomic mass unit'** (or sometimes **'universal atomic mass unit'**) is the official SI-recognized name for 'u' **Answer: A = "Unified Atomic Mass Unit"** (or "Universal Atomic Mass Unit") This replacement standardizes the unit across all scientific disciplines and aligns with international measurement conventions.