Properties of the elements mainly depend on their __________. (electronic configuration/atomic masses)

Explanation

To solve the question "Properties of the elements mainly depend on their __________. (electronic configuration/atomic masses)", we can follow these steps:

### Step 1: Understand the Question
The question is asking what primarily influences the properties of elements. We have two options: electronic configuration and atomic masses.

**Hint:** Think about what determines how elements behave chemically and physically.

### Step 2: Recall the Modern Periodic Law
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