The number of electrons in the outermost shell of the atom of an element tells the _________ to which the element belongs. (group/period)

Explanation

To solve the question, "The number of electrons in the outermost shell of the atom of an element tells the _________ to which the element belongs. (group/period)," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the significance of the number of electrons in the outermost shell of an atom. We need to determine whether this number relates to the "group" or "period" of the periodic table.

**Hint**: Think about what characteristics of an element are determined by the electrons in its outermost shell.

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