The number of ________ is the same across a period but increases when moving down a group?

Question

Quizplus · Accepted Answer

As you move from left to right across the periodic table (period), the atomic number increases. As you move from top to bottom (group), the number of filled electron shells increases.
You may use the diagram below as a visual reference for the organization of elements in the periodic table.
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The Number of ________ Is the Same Across a Period