Electron shells are important parts of how atoms are structured. You can think of them like the floors in a building, where each floor has room for a certain number of people (electrons) to live.

Here’s a simple breakdown:

• The first shell, which is closest to the center of the atom, can hold up to 2 electrons.
• The second shell can hold up to 8 electrons.
• The third shell can hold up to 18 electrons.

Now, let’s dive a bit deeper:

1. Shells: Electrons fill these shells based on energy levels. When an atom gets more energy, its electrons can move up to higher shells.

2. Subshells: Each shell has smaller areas called subshells. These are labeled with letters (s, p, d, f) and hold different amounts of electrons:

   • The s subshell can hold 2 electrons.
   • The p subshell can hold 6 electrons.
   • The d subshell can hold 10 electrons.
   • The f subshell can hold 14 electrons.

Knowing how electrons are arranged, or their configuration, can help us understand how atoms work and how they bond with each other.

For example, carbon, which has the atomic number 6, has an electron arrangement of 1s² 2s² 2p². This tells us how carbon's electrons are spread out in its shells and subshells, which affects how it behaves in chemical reactions.