1. Creation of the Elements Chapter 4 Section 4

2. http://www.astro.utoronto.ca/~mcclure/problems/problems.html Hydrogen was formed from energy after the Big Bang As the universe cooled, some of the energy was converted into protons, neutrons and electrons. As the universe cooled, some of the energy was converted into protons, neutrons and electrons. These particles formed the first atoms, mostly H but also some He. These particles formed the first atoms, mostly H but also some He. In this early process, energy was converted into matter according to the equation In this early process, energy was converted into matter according to the equation E = mc 2

3. The hydrogen atoms began to form stars Gravitational attraction pulled the H atoms closer and closer together. Gravitational attraction pulled the H atoms closer and closer together. Clouds became denser, pressures and temperatures at the center of the stars increased, and stars were born. Clouds became denser, pressures and temperatures at the center of the stars increased, and stars were born. http://homepages.wmich.edu/~korista/stargal-images/first_stargals.jpg

4. Elements 2-92 were created by nuclear fusion The interior of stars is very hot, giving the energy required for nuclei to come close enough together to undergo nuclear fusion. The interior of stars is very hot, giving the energy required for nuclei to come close enough together to undergo nuclear fusion. Mass is not conserved, but is converted to energy according to the equation E = mc 2. Mass is not conserved, but is converted to energy according to the equation E = mc 2. In the first phase, 4 protons ( 1 H) can come together to form He. In the first phase, 4 protons ( 1 H) can come together to form He. http://www.ichthus.info/BigBang/intro.html

5. Helium formed in fusion can undergo further fusion reactions to form heavier elements.

6. These Elements are Released into Space The specific elements formed in a star depend on The specific elements formed in a star depend on Temperature of star Mass of star Stage of Development Eventually the fuel is used up, and often the star explodes, releasing its elements into space to be used in new stars or planets. Eventually the fuel is used up, and often the star explodes, releasing its elements into space to be used in new stars or planets. http://nexus.polaris.net/services/image-archive/space/interstellar/?D=A

7. Artificial elements are created by transmutation Elements 93-100 were created by bombarding nuclei with charged particles such as protons and alpha particles. Elements 93-100 were created by bombarding nuclei with charged particles such as protons and alpha particles. These charged particles can be accelerated by a cyclotron. These charged particles can be accelerated by a cyclotron. This picture shows a cyclotron at UC, Berkeley in 1942. This picture shows a cyclotron at UC, Berkeley in 1942. http://www.flickr.com/photos/12567713@N00/124523846/

8. The First Transmutation The first transmutation that was identified was in 1919: The first transmutation that was identified was in 1919: 14 N + 4 He  17 O + 1 H Nitrogen was transformed into oxygen

9. Superheavy elements Higher-atomic-mass elements (greater than atomic number 100) were created by crashing nuclei into each other using accelerators such as synchrotrons. Higher-atomic-mass elements (greater than atomic number 100) were created by crashing nuclei into each other using accelerators such as synchrotrons. 12 C + 244 Cm  254 No + 2 1 n carbon curium nobelium neutrons carbon curium nobelium neutrons These elements are very unstable. e.g. Only 3 atoms of element 109 were created and they existed for only 0.0034 seconds.