Periods in the periodic table. In each period (horizontal row), the atomic numbers increase from left to right. The periods are numbered 1 through 7 on the left-hand side of the table. Elements that are in the same period have chemical properties that are not all that similar.
Also to know is, what does the period number stand for?
A period in the periodic table is a horizontal row. All elements in a row have the same number of electron shells. Arranged this way, groups of elements in the same column have similar chemical and physical properties, reflecting the periodic law.
What does the period number tells us?
The electronic structure of an atom describes the arrangement of its electrons around the nucleus. There are two links between an atom's electronic structure and its position in the periodic table: The number of occupied shells is the same as the period number(row in the table)
What is a period in number?
"Period" is just the name for the rows of the periodic table. ("Group" is for the columns.) Thus, hydrogen is in period 1, lithium is in period 2, sodium is in period 3, and so on.