Rows are called periods. They contain same number of shells.
An elements period is its row in the Periodic Table.
An elements period is its row in the Periodic Table.
An elements period is its row in the periodic table.
a horizontal row is called a period.a vertical row is called a group
A row in the periodic table is called a period. Columns are groups.
A row in the Periodic Table is called a period. Columns are groups.
A row in the Periodic Table is called a period. Columns are groups.
A horizontal row on the periodic table of elements is called a period.
Hydrogen is found in group 1 row 1 of the periodic table
A period is a row of elements on the periodic table.
A period is a row in the periodic table of elements.
In a periodic table a row is a period.