Nuclear _____________of atom is changed Particles or energy is absorbed or emitted from nucleus Can involve one atom or multiple atoms New elements can be made if ______________ changes (transmutation) Nucleus remains _______________ ____________ are sometimes gained or lost __________ involves multiple atoms New compounds are made when elements are rearranged Chemical

Matter and energy can be exchanged according to the equation _________________ E = energy (unit is J) m = mass (must be in ______) C = speed of light (3.00 x 10 8 m/s)

Particles or energy emitted during nuclear reactions Two categories Non-Ionizing Not powerful enough to knock electrons out of atom For example: Radio waves, microwaves, infrared Ionizing Powerful enough to knock electrons out of atoms For example: upper limits of UV, x-rays, gamma rays, nuclear particles

R-E-A-D Radiation- amount of radiation released by material; measured in curie (Ci) Exposure- amount of radiation traveling through air; measured in roentgen (R) Absorbed- amount of radiation absorbed by material; measured in rad (radiation absorbed dose) Dose equivalent- number that takes into account amount absorbed and its medical effect; measured in rem (roentgen equivalent man)

Elements 84-end of table (93-end of table are man-made) ____________ makes them unstable Isotopes with large differences between __________________________________ Difference between proton and neutron numbers make them unstable

For elements 1-20, having a 1:1 ratio of protons: neutrons is most stable. For larger atoms, more neutrons are needed for the isotope to be stable.

Element symbol is written with the following numbers in front Mass number (# of protons + # of neutrons) as a superscript Atomic number (# of protons) as a subscript

Alpha (  ) particles Beta (  ) particles Gamma (  ) rays

Can be called ______________ Contain 2 protons and 2 neutrons (look like a helium nucleus) Very _____ (compared to other types of radiation) Easily blocked by a piece of ___________ Does not usually cause external damage but can cause great internal damage if inhaled, ingested, or enters by some other means

Can be called beta decay or beta negative emission Emitted because a neutron is changed into a proton + electron in the nucleus Smaller than alpha particles, but still large Can be blocked by small amounts of lead Most harmful inside the body

No mass or charge, just energy released from atom Very small Can only be blocked by thick blocks of lead

Reactants and products are written with their A and Z numbers A numbers must balance ________________ Z numbers must balance ________________

Series of reactions that a radioactive element will go through until it reaches stability _________ nuclide- heaviest isotope in the series ____________ nuclides- isotopes created during the decay

Creation of a larger nucleus from two smaller nuclei Particles must be moving very fast Power in “Hydrogen” bombs and stars (including our sun)

Splitting of a large nucleus into two nuclei Usually done by bombarding with ____________ Creates chain-reaction by releasing more neutrons Critical mass- amount of radioactive material needed to sustain the reaction Powers nuclear bombs and nuclear power plants

Rate at which radioactive element decay occurs If graphed, it will form a _____________ curve

Amount of time for half of a radioactive sample to decay Set half-life for each isotope Time passedHalf –lives passed Amount of original element left

Power Weaponry Medical Applications Short half-lives work best, minimizes radiation exposure Dating Various nucleotides are used depending on expected age of and composition of material C-14 (radioactive isotope) Must be used on materials that’s came from living things Must be used on items less than 50,000 years old since half- life of C-14 is 5,730 years