The horizontal rows in the periodic table are called
The horizontal rows in the periodic table are called
Explanation
The periodic table organizes elements in rows and columns. The horizontal rows going from left to right are called periods, numbered 1 through 7.
Each period represents elements with electrons filling the same outermost energy level. Period 1 has one energy level, period 2 has two, and so on.
Vertical columns are called groups or families because elements in the same column have similar chemical properties. Periods show how properties change across the table.