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.

The answer is The number before the A at the top of a column shows how many dots to draw in the diagram.

Answer;

The number before the A at the top of a column shows how many dots to draw in the diagram.

Explanation;Electron dot structures are structures in which electrons are represented by dots placed around a chemical symbol. Therefore, in a dot diagram only the symbol for the element and the electrons in its outermost energy level are shown.The reason as to why valence electrons are the only ones used in dot diagram is because; they are the only ones involved in chemical reactions and bonding, to make it easier to decide what it could be bonded to and its characteristics. Also to make it easier identify its placement on periodic table.

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.