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What information on the periodic table is used to complete electron dot diagrams?

The number before the A at the top of a column shows how many dots to draw in the diagram.
The number before the B at the top of a column shows how many dots to draw in the diagram.
The number at the left of each row shows the number of valence electrons that are in atoms of elements in that row.
The number at the left of each row shows how many dots to draw above the symbol for elements in that row.

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Answered by GPT-5 mini AI
The first statement only.

Explanation: For main-group elements, the group number shown as "1A, 2A, …, 7A, 8A" tells the number of valence electrons (and thus the number of dots in a Lewis/electron‑dot diagram). The B group numbers (transition metals) and the row/period numbers do not reliably give the valence‑electron count used for Lewis dots. For example, C is in group 4A → 4 dots; O is in 6A → 6 dots.