DO NOW

1. Objective: explain how elements are created in stars and identify the results of fusion in large stars. DO NOW 1)What is plasma?

2. Where do elements come from? • Scientists look at stars to get this answer • Using stars scientists have formulated theories about how matter originated on Earth.

3. Plasma • At extreme temperatures matter does not exist as a solid, liquid, or gas. • Matter exists as plasma in the sun and stars • Plasma is a state of matter that has a gas-like mixture of free electrons and atoms stripped of electrons.

4. Plasma • Can be produced by high voltage electricity • Forms inside a fluorescent light when it is turned on. • Sun’s plasma is under extremely high pressure.

5. When Nuclei Combine • Under normal circumstances the positively charged nuclei repel one another. • The pressure is so high in stars that it forces the nuclei to come close and even collide with one another. • When colliding nuclei have enough energy, they combine.

6. Nuclear Fusion • Process which two atomic nuclei combine to form a larger nucleus and release huge amounts of energy in the process. • Occurs in stars on a huge scale • Combines smaller nuclei with larger nuclei to create heavier elements

7. Nuclear Fusion • Stars join Hydrogen nuclei to form elements as large as oxygen • Eventually the star shrinks and the elements spread into space • This forms a nebula: cloud-like region in space

8. Elements from Large Stars • As larger stars age they get hotter and can form elements as heavy as Iron • Elements heavier than Iron are produced when a supernova occurs • Supernova is a huge explosion that breaks apart a massive star and creates temperatures as high as 1 billion degrees Celsius.

9. Objective: explain how elements are created in stars and identify the results of fusion in large stars.