A row on the periodic table

A row on the periodic table is also known as a period. The periodic table has seven periods.

Step 1: Understanding the Periodic Table The periodic table is a tabular arrangement of chemical elements, organized based on their atomic number, electron configuration, and recurring chemical properties. Elements are listed in order of increasing atomic number, which corresponds to the number of protons in an element's atomic nucleus.

Step 2: Identifying a Period A period in the periodic table is a horizontal row. All elements in a period have the same highest unexcited (ground state) electron energy level. The period number of an element signifies the highest energy level an electron in that element occupies (in the unexcited state).

Step 3: Number of Periods There are seven periods in the periodic table, with each one beginning at the far left. A new period begins when a new principal energy level begins filling with electrons.

Step 4: Properties of Elements in a Period Across a period, the properties of elements gradually change. This is due to the increase in the atomic number and the addition of electrons and protons. For example, elements on the left side of the periodic table tend to be metallic, while those on the right tend to be nonmetallic.

Step 5: Examples of Periods The first period contains only two elements: hydrogen and helium. The second period, from lithium to neon, contains eight elements. The number of elements in a period increases as you move down the periodic table because there are more available energy levels.