1. Aim: How can we explain the four fundamental forces and the standard model? Do Now: List all the subatomic particles that you can think of

3. Four Fundamental Forces Weakest Strongest Gravitational Weak nuclear Electromagnetic Strong nuclear

4. Gravitational Responsible for shaping the large scale structure of the universe (galaxies, stars, etc.)

5. Weak Nuclear Responsible for –Radioactive decay –Fusion of the sun –Conversion of neutrons into protons in the nuclei

6. Electromagnetic Includes electrostatic and magnetic forces

7. Strong Nuclear Holds the nucleus together by resisting the repulsion of protons. Very short range.

9. The Standard Model All matter is composed of Hadrons and Leptons

10. Leptons Made up of charged and neutral matter Cannot be broken down (as of now); it is a fundamental particle Experience weak force interactions

11. Charged Leptons electron muon tau Neutral Leptons electron neutrino muon neutrino tau neutrino

13. Hadrons Subatomic particles composed of quarks (the fundamental particles of the Standard Model) Experience strong force interactions

15. Mesons Unstable Consist of one quark and one anti-quark

16. Baryons Mass is equal to or greater than a proton Consists of protons and neutrons (the most common), and other types of matter

17. Quarks Smallest known unit of matter Cannot be isolated Exists as: –baryon (3 quarks) or –meson (quark and anti-quark)

18. Fundamental Rule of Standard Model: For every particle, there exists an anti- particle

19. Quark Types

20. Antiquarks Same mass, opposite charge Represented with a line on top – Represents an anti-up quark –Charge is -

21. Protons and Neutrons Are made of up and down quarks Proton: charge is +1 –up, up, down (uud) –(+2/3) + (+2/3) + (-1/3) = +1 Neutron: charge is 0 –up, down, down (udd) –(+2/3) + (-1/3) + (-1/3) = 0