EVERYDAY SCIENCE

Detailed explanation-1: -What do the rows represent? The rows in the periodic table correspond to the number of energy levels of the atoms in that row. If you look at the chart, you can see that the atoms in the first row have one energy level. The atoms in the second row have two energy levels and so on.

Detailed explanation-2: -The highest energy level number (1 through 7) for the electrons in an atom corresponds to the period (or row) in the periodic table to which that atom belongs. Because there are 7 periods in the table, there are 7 energy levels.

Detailed explanation-3: -The table has seven rows and 18 columns. Each row represents one period; the period number of an element indicates how many of its energy levels house electrons. Sodium, for instance, sits in the third period, which means a sodium atom typically has electrons in the first three energy levels.

Detailed explanation-4: -The atoms in the first period have electrons in 1 energy level. The atoms in the second period have electrons in 2 energy levels. The atoms in the third period have electrons in 3 energy levels. The atoms in the fourth period have electrons in 4 energy levels.