2. If the sun is a burning ball of gas … just what gas is it burning? Warmup Question:

3. The Sun Components & Nuclear Fusion

4. The Sun’s Composition The sun is a massive, luminous ball of burning gas. –Remember – burning does not destroy matter, it releases energy and changes the matter it into something else: wood  ashes, dough  cookies Gasses found in the Sun: –Hydrogen75% –Helium24% –Oxygen<1% –64 more elements make up the rest Our book lists Hydrogen at 75% - most other sources are closer to 71%.

5. The Periodic Table

6. Nuclear Fusion “Normal” Hydrogen atom (75% of the sun) One PROTON One ELECTRON Inside the Sun – the intense heat strips the atom of its electron. This is now a 1 H Hydrogen Nucleus P e

7. Nuclear Fusion – Part 1 PPN p One proton loses its charge and becomes a neutron. This is now 2 H Hydrogen. A positron is formed & released. Two 1 H Protons collide! n A neutrino is formed & released. Energy Released!!

8. Nuclear Fusion – Part 2 This forms 3 He HELIUM – a NEW element is formed! Helium is 24% of the sun. Hydrogen 2 H colides with another loose Proton. N PP Energy Released!!

9. Nuclear Fusion – Part 3 Two Protons are knocked loose. This forms 4 He HELIUM. Helium 3 He collides with another Helium 3 He NPPNPP Energy Released!! Those loose Protons are now a 1 H Hydrogen Nucleus – they are recycled back into the Hydrogen pool to be turned into Helium again.

10. Review Gasses found in the Sun: –Hydrogen75% –Helium24% –Oxygen<1% –64 more elements make up the rest Scientists estimate the age of a sun by how much hydrogen it has left.

11. Nuclear Fusion (6) Hydrogen  (1) Helium + (2) Hydrogen (plus a few positrons and neutrinos released) Produces most of the sun’s energy Energy released causes the sun to shine and gives off high temperatures Elements other than hydrogen can fuse In stars that are hotter than the sun, energy is produced fusing carbon, nitrogen, and oxygen.

12. Einstein 1905 proposed that a small amount of matter can yield a large amount of energy. Nuclear fusion was unknown. The nucleus of an atom was unknown. And yet his theory explained how the sun can give off so much energy without burning out too soon.

13. Einstein & E=mc 2 E = energy m = mass c = speed of light Einstein’s equation can be used to calculate the amount of energy produced from a given amount of matter. The sun turns more than 600 million tons of hydrogen into helium every second.

14. So – do you know now? If the sun is a burning ball of gas … just what gas is it burning? Warmup Question: