_____________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
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