1. Monday, May 4 th m.socrative.com 9bff6d58 Intro to Nuclear Chemistry

2. Nuclear Chemistry Radioactivity Radiation Nuclear reaction Radioactive decay Alpha radiation Alpha particle Nuclear equation Beta radiation Beta particle Gamma ray Radioisotopes X-rays Penetrating power

3. Thursday May 7th Go to m.socrative.com 9bff6d58 Radioactive Decay

4. Radioactive decay is the conversion of one element into another element The element’s atomic number is altered This is also called TRANSMUTATION

5. Nuclear Stability Protons and neutrons are held together in the nucleus by a strong nuclear force The stability of a nucleus is correlated to its n/p ratio Example: helium

6. Nuclear Stability The Band of Stability is the area on the graph where all stable nuclei fall. Anything outside of this band is considered radioactive and will decay to achieve stability.

7. Nuclear Stability The Band of Stability ends at lead-208; all elements with atomic numbers greater than 82 are radioactive.

8. Types of Decay Type of decay is generally determined by where the radioisotope falls on the chart Above the band means it has too many neutrons Below the band means it has too many protons

9. Types of Decay Beta Decay Decreases the number of neutrons in the nucleus A neutron is changed to a proton, and an electron is emitted (β or e - ) (charge of -1) (n  p + e - ) Leads to stable nucleii Example: Carbon-14 to Nitrogen-14

10. Types of Decay Alpha Decay Both neutrons and protons must be reduced to achieve stability, so it emits alpha radiation An alpha particle is the same as a Helium nucleus – 2 protons, 2 neutrons Has a charge of +2 Slow-moving because of size

11. Types of Decay Positron Emission Basically the opposite of Beta Decay A proton is changed into a neutron and a positron is emitted A positron is a particle with the same mass as an electron but has a positive charge (β + or e + ) p  n + e +

12. Types of Decay Electron Capture Occurs when the nucleus of an atom draws in a surrounding electron This electron will combine with a proton to form a neutron Atomic number decreases by 1 p + e -  n

13. Band of Stability C B A D 82 Number of neutrons Number of protons