1. Where Did the Elements Come From?
Section 4.4

2. Natural and Synthetic Elements
Not all elements are found on Earth – some were found in the spectra of the stars
Synthetic elements have been created by man

3. Stars Big bang THEORY Explosions Temperature only E could exist
Cooling  matter produced

4. Nuclear Reactions
Rxn involving a change in the composition of the nucleus of an atom
Centers of stars, H nuclei fused to form He
Nuclear fision takes place at extremely high temps

5. Stars As H is used up, the star shrinks and becomes hot
This causes He to fuse and form elements with higher atomic numbers
Fe and Ni are the largest formed by this (believed to be in Earth’s core)

6. The Sun
When this happens in a sun sized star, it collapses and expands as a red giant
When this forms, other parts of nuclei are produced and larger elements than Fe and Ni are produced

7. Artificial Elements
Transmutation – the process of changing one nucleus into another by radioactive disintegration or bombardment w/ other particles

8. Transmutations
Transmutation rxns were discovered by bombarding elements with alpha particles
Cyclotron – device that shoots charged particles with E pulses at elements

9. Synchrotron Used to create superheavy elements
Particles in cyclotron can only reach max speed until it arrives for the next pulse too late.

10. Synchrotron Matches the acceleration of the particles
Accelerates fewer types of particles but reaches higher E than a cyclotron

11. Superheavy Elements
When particles interact head on, they allow massive nuclei to interact and create superheavy elements.
SHE = element with atomic # higher than 106

12. Superheavy Elements
Some of these elements last only for a few seconds.
When meitnerium was created, it lasted for only seconds.