The elements given below are arranged in order of increasing atomic masses.
F, Na, Mg, Al, Si, P, S, Cl, Ar, K
This arrangement of elements is an illustrator of which law of classification of elements.

Explanation

To determine which law of classification of elements is illustrated by the arrangement of the elements F, Na, Mg, Al, Si, P, S, Cl, Ar, K in order of increasing atomic masses, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Elements and Their Atomic Masses**:
- List the elements in the given order: F (Fluorine), Na (Sodium), Mg (Magnesium), Al (Aluminium), Si (Silicon), P (Phosphorus), S (Sulfur), Cl (Chlorine), Ar (Argon), K (Potassium).
- Note their atomic masses:
- F: 19
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