The periodic table is like a big map of elements. It has rows called periods and columns called groups. Each row shows the main energy level of the electrons in an atom.

1. Electron Configuration:

   • This is how we describe where the electrons are located in an atom.
   • Elements in the same row have their electrons in the same energy level.

2. Structure of Periods:

   • There are seven rows in the periodic table.
   • As you go down a row, the atomic number goes up and the elements usually have similar ways their electrons are arranged.

3. Trends Across Periods:

   • When you move from left to right in a row, both the number of protons and electrons goes up.
   • For example, the first row has 1 element (Hydrogen) and 2 elements (Helium), but the second row has 8 elements (from Lithium to Neon).

4. Impact on Chemical Properties:

   • How elements act is affected by their electron configuration.
   • Elements on the left side of a row often lose electrons easily, while those on the right side usually gain or share electrons.

In simple terms, the rows (or periods) in the periodic table help us understand how the electrons are set up and what the elements are like.