Periods
Periods :P
columns are the horizantal lines and groups are are the vertical lines
Vertical columns are called groups. Horizontal rows are known as periods.
Periods
The rows in the periodic table are called periods. There are 7 periods in periodic table.
There are 7 periods in the modern periodic table.
The Periodic Table is arranged like it is for a specific reason. It is probably called the Periodic Table because it is made up of "periods" or horizontal rows.
rows. the vertical columns are called periods
Periods.
These are called periods. Although some chemists simply call them rows.
they are called periods, but most people will know if you call them rows
Horizontal rows are called periods. There are 7 periods in periodic table.