Atomic number is considered to be a more appropriate parameter than atomic mass for classification of elements in a periodic table. Why?
How does metallic character of elements vary on moving from (i) left to right in a period? (ii) from top to bottom in a group? Give reasons for your answers.

Explanation

### Step-by-Step Solution:

**1. Understanding Atomic Number vs. Atomic Mass:**
- The atomic number of an element is defined as the number of protons (and electrons in a neutral atom) in its nucleus. It is a unique identifier for each element.
- Atomic mass, on the other hand, is the weighted average mass of an element's isotopes and can vary due to the presence of isotopes.

**2. Why Atomic Number is Preferred:**
- Atomic number is a fundamental property that directly relates to the electronic configuration of an element.
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