New Recording 52

Atomic Structure

• Atoms: Basic unit of matter made up of neutrons, protons, and electrons.

  • Nucleus: Contains protons (positively charged) and neutrons (uncharged).

  • Electrons: Negatively charged particles that orbit around the nucleus in shells.

Electron Shells

• Electron arrangement:

  • First shell: holds 2 electrons.

  • Second shell: holds 8 electrons.

  • Third shell (and beyond): holds 8 electrons, but detail beyond this is not emphasized.

Main Elements of Life

• Four primary elements make up 96% of human body: