Atomic Structure

Introduction

• Lecture on the components of atoms: proton, electron, neutron.
• Reminder to subscribe for more conceptual lectures.

Basic Concepts

• Atoms: Fundamental building blocks of matter (e.g., salt, sugar, water, plants, animals, humans).
• Atoms consist of three particles:
  • Proton
  • Electron
  • Neutron

Atomic Structure

• Atoms are spherical, similar to a ball.
• Nucleus: Dense central part of an atom.
• Energy Levels/Shells: Fixed parts around the nucleus.
  • Protons and neutrons are in the nucleus.
  • Electrons revolve around the nucleus, similar to planets around the sun.

Forces and Charges

• Electrostatic Force: Force between positively charged protons and negatively charged electrons.
  • Causes electrons to revolve around the nucleus.
• Neutron: Neutral particle (no charge).

Atom's Neutrality

• An atom as a whole is electrically neutral.
• Example: Hydrogen Atom
  • 1 proton (+1 charge) in the nucleus.
  • 1 electron (-1 charge) revolving around the nucleus.
  • Positive and negative charges cancel out, making the atom neutral.

Balance of Charges

• Number of Protons = Number of Electrons in any atom.

Role of Neutrons

• Neutrons separate protons to minimize repulsion.
• Example: Helium Atom
  • 2 protons (positive charge) repel each other.
  • 2 neutrons separate the protons, minimizing repulsion.

Electron Shells

• Example: Lithium Atom
  • 3 protons in the nucleus.
  • 3 electrons revolving around the nucleus.
  • Two shells in a lithium atom:
    • First shell: Holds 2 electrons.
    • Second shell: Bigger, holds up to 8 electrons.
• Energy Levels: K, L, M, N.
• Minimize repulsion among electrons by arranging them in different energy levels.

Summary

• Atoms consist of protons, electrons, and neutrons.
• Atoms are electrically neutral (Protons = Electrons).
• Neutrons minimize repulsion among protons in the nucleus.
• Multiple shells reduce repulsion among electrons.