_____________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 108 m/s)

Particles or energy emitted during nuclear reactions

Two categoriesNon-Ionizing

Not powerful enough to knock electrons out of atom

For example: Radio waves, microwaves, infrared

IonizingPowerful enough to knock electrons

out of atomsFor example: upper limits of UV, x-

rays, gamma rays, nuclear particles

R-E-A-DRadiation- 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 largeCan be blocked by small amounts of leadMost harmful inside the body

No mass or charge, just energy released from atom

Very smallCan 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 fastPower in “Hydrogen” bombs and stars

(including our sun)

Splitting of a large nucleus into two nucleiUsually done by bombarding with ____________Creates chain-reaction by releasing more

neutronsCritical mass- amount of radioactive material

needed to sustain the reactionPowers 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 passed

Half –lives passed

Amount of original element left

0 0 100

12.26 1 50

24.52 2 25

36.78 3 12.5

PowerWeaponryMedical Applications

Short half-lives work best, minimizes radiation exposure

DatingVarious nucleotides are used depending on

expected age of and composition of materialC-14 (radioactive isotope)

Must be used on materials that’s came from living thingsMust be used on items less than 50,000 years old since

half-life of C-14 is 5,730 years