AKA Radioactive DECAY or NUCLEAR DECAY Radioactivity AKA Radioactive DECAY or NUCLEAR DECAY

Radioactive Decay Radioactive decay takes place when an unstable atom’s nucleus spontaneously changes by emitting radiation including alpha particles, beta particles, and gamma rays.

TRANSMUTATION This occurs when one element changes into another element. Ernest Rutherford and Fredrick Soddy were able to perform transmutation in 1901. When alpha and beta decay occur the resulting daughter atom is a different element than the parent atom.

Each type of radiation can damage tissue… Paper Are the largest particles of the three. Aluminum Foil Thick Material Lead Steel Concrete How can you protect yourself from radiation?

Nuclear Reaction Equations When writing nuclear reaction equations, use the following format: X Parent Atom Y Daughter Atom A Atomic Mass Z Atomic Number

Alpha Decay Alpha decay is the most common type of radioactive decay. In alpha decay, the parent atom emits an alpha particle from the nucleus. An alpha particle is made up of 2 protons and 2 neutrons, so it is also known as a helium nucleus. The symbol for alpha decay Parent Atom Daughter Atom

Determine the products of the alpha decay of the parent atoms. Practice Determine the products of the alpha decay of the parent atoms.

Beta Decay: There are 3 types of Beta Decay Beta-Negative Decay Beta-Positive Decay Electron Capture A neutron converts to a proton + electron. The electron is ejected from the nucleus. A proton converts to a neutron + positron. The positron is ejected from the nucleus. An electron is captured by the nucleus. The electron and one proton convert into a neutron. Positron for B+ Electron for B-

Gamma Decay Gamma decay usually occurs after alpha or beta decay, when the nucleus of the atom is excited (has extra energy). The nucleus releases a “gamma ray” which is a photon. No actual particle is released, so the daughter atom is the same as the parent atom. gamma ray photon

Determine the products of the gamma decay of the parent atoms. Practice Determine the products of the gamma decay of the parent atoms.

Fission and Fusion

FUSION: Joining two or more things together Nuclear Fusion takes place when small nuclei join to make larger nuclei. An incredible amount of energy is released through fusion reactions Fusion reactors are being developed in order to harness this energy to produce electricity In stars, isotopes of hydrogen (deuterium and tritium), in high temperatures and under extreme pressure, fuse to form helium: This is how the elements were made. Fusion occurs in atoms smaller than iron.

Fission: Splitting or breaking down into smaller parts Nuclear fission occurs when an atom breaks down into smaller atoms. Occurs in atoms larger than iron. Uranium is used in fission reactions. Space probes use fission as a heat source. The energy from fission can be converted into ELECTRICITY! A LOT of energy is released! Neutrons are often emitted through fission which can lead to a chain reaction.

AKA Radioactive DECAY or NUCLEAR DECAY Half life AKA Radioactive DECAY or NUCLEAR DECAY

Half-Life Half-Life is the average amount of time it takes for a radioactive substance to decay to half its original mass. What would the graph of the isotope Y-100 look like when going through half-life? Osmium-183 has a half-life of 12.0 hours. Complete the table for an initial sample size of 180 grams. Now using the graph, estimate the number of half-lives it takes for the sample to decay to: 40% of its original mass 10% of its original mass Label the parts of the formula! What should the units for half life be? A and A0 can be measure in any mass unit (g, kg) as long as they are the same unit. Likewise for t, h in time (s,h)