Nuclear Chemistry

"in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity” Nobel Prize in Physics 1903 Nobel prize in physics for discovery of spontaneous radioactivity. Marie Curie was given a nobel prize in chemistry for her work in radioactivity (she discovered polonium and radium) In recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element" Marie Curie received the Nobel Prize for Chemistry in 1911 Henri Becquerel Pierre Curie Marie Curie

What causes radiation or nuclear decay? The presence of too few or too many neutrons compared to protons leads to an unstable nucleus.

Reminder Mass number=Protons + Neutrons Atomic number=Protons

Radioisotopes Radioisotopes - Isotopes that have an unstable nucleus

Nuclear Reactions and Radiation. Nuclear Reactions: Reactions in which radioisotopes gain stability by undergoing changes. Radiation : These changes are accompanied by the release of large amounts of energy. Transmutation: the conversion of one chemical element or isotope into another through nuclear reaction. Radioisotope Nuclear Reaction Radiation

Radioactive Decay Radioactive Decay - The process where an unstable nucleus loses energy by emitting particles of radiation.

Alpha Decay Consists of a helium nuclei that has been emitted from a radioactive source. Symbol: Example:

Beta Decay A neutron is converted to a proton and an electron. The electron is emitted, the proton stays. Particle Emitted: Symbol: Example:

Gamma Radiation Gamma radiation is emitted often times along with alpha and beta radiation. It has no mass or electrical charge. It is high energy radiation and is very dangerous! Particle: Symbol:

Radioactive particles Penetrating power:

Summary Property Alpha Radiation Beta Radiation Gamma Radiation Composition (Helium Nucleus) Electron High energy electromagnetic radiation Symbol γ Charge 2+ 1- Mass 4 1/1837 Common Source Radium-226 Carbon-14 Cobalt-60 Penetrating Power Low Moderate Very high Shielding Paper, clothing Metal foil Lead, concrete

Homework

Radioactivity and Radioactive Decay Today’s Objective Write nuclear decay equations to depict the nuclear decay of radioisotopes. Predict the type of nuclear decay using the band of stability.

How do we write nuclear equations? A nuclear equation will look like this: 1. Isotope  particle + element Because of the law of conservation of mass, all mass numbers and atomic numbers, or the tops and bottoms of the complete symbols, must balance on either side of the arrow. 2. When you write your equation, balance your mass numbers followed by your atomic numbers.

Nuclear Equations (cont) Beta Decay K 42 19 e Ca 0 -1 20 42 = 0 + 42 and 19 = -1 + 20 Gamma Decay . Does not change the element. Pu 240 94 Pu 240 94

Writing Nuclear Decay Equations Nuclear Equations: Practice   1. 2. 3.

Word Equations 4. Write the equation of lead-210 undergoing alpha decay. 5. Write the equation where lead-210 emits a beta particle. 6. Show the transmutation of uranium-237 as it undergoes alpha decay. What is the nuclide that is produced?

Homework: page 20

Transmutation The process where a nucleus becomes a NEW nucleus because the number of protons has been changed. What is the only type of radiation that does NOT change the atomic number? Gamma (λ)- it has 0 mass and 0 charge, therefore does not affect the nucleus size! 

Fission and Fusion Show “Nuclear Power and Its Effect on the World” http://www.youtube.com/watch?v=ur6Kb62Ci5k

Fission and Fusion Fission Fusion Bombard nuclei with neutrons Atom falls apart Lots of energy evolved Can create a chain reaction Instantaneous Ex:Atomic Bombs, nuclear reactors Requires input of energy Two nuclei combine to make new atom of Helium Releases more energy than fission Difficult to control Ex: Sun uses fusion

Fission Reaction/ Chain Reaction

FUSION

In the News!!!!! 60 Minutes Report Fukushima Nuclear Power Plant Japan https://www.youtube.com/watch?v=BdbitRlbLDc In the News!!!!! 60 Minutes Report Fukushima Nuclear Power Plant Japan http://www.youtube.com/watch?v=z6cYE7PwMik https://www.youtube.com/watch?v=x4TnfaNAxF4