Question

Reference to the long form of the periodic table fills in the blanks with appropriate words.

The number of electron shells around the nucleus of an atom represents its -------- in the periodic table

Answer 1

Modern periodic table:

• The modern periodic table is an arrangement of all the elements known in accordance with their increasing atomic number and recurring chemical properties.
• It is a tabular display of 118 chemical elements which consists of horizontal rows called periods and vertical columns are called groups.
• All elements in a group have the same number of valance electrons, and in period elements have the same number of electron shells.

Therefore, the number of electron shells around the nucleus of an atom represents its period number in the periodic table.