Name the scientist who first of all showed that atomic number of an element is a more fundamental property than its atomic mass.

Explanation

To answer the question, we need to identify the scientist who established the atomic number as a more fundamental property than atomic mass in the context of the periodic table. Here’s the step-by-step solution:

### Step 1: Understand the Historical Context
- Before the modern understanding of the periodic table, elements were arranged based on their atomic masses. Dmitri Mendeleev created a periodic table that primarily used atomic mass to organize elements.

**Hint:** Consider how elements were classified before the introduction of atomic number.

### Step 2: Identify the Shift in Understanding
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