Types Of Radiation Flashcards
Nucleons are bond together by
Nuclear force
Relation of distance and nuclear force
Close distance= strong nuclear force
Potential energy change between tow nucleons against
Distance
Negative P.E. Indicates which force between the nucleons
Attractive force
Stable nuclei have a neutron/proton ratio equal to
1:1 and 1.5
If the neutron-proton ratio is less than 1:1 or greater than 1.5:1 ratio this nucleus is called
Unstable
Transition between atomic states excitates
Visible light
X-ray
Transition between nuclear states excitates
Gamma rays
Two factors that govern the ratio of neutrons to protons in a nucleus
1- n-p force > n-n —> favors equal number of protons and neutrons. LIGHT NUCLIDES
2- repulsive force between protons. HEAVIER NUCLIDES
Nuclear binding energy
Energy required to keep the nucleus together
Above belt
Beta emission
Below belt
Alpha emission
Why the measured mass of a nucleus is always smaller than the combined masses of its parts
Binding energy is equal to that difference
In light elements relation between binding energy and atomic mass
binding energy increases as atomic mass increases
In heavier elements relation between binding energy and atomic number
Binding energy decreases as atomic number increases
Radiation types
Ionizing radiation
Non-ionizing radiation
Ionizing radiation
Particular— alpha and beta
Electromagnetic waves — X and gamma
Non-ionizing
UV
Visible
Infrared
Microwaves
Radiowaves
If the energy transferred is not sufficient to cause ionization what occurs
Excitation
The radiation particles themselves may be
Charged (directly ionizing)
Not charged (indirectly ionization)
Directly ionizing radiation
Electrically charged particles having sufficient K.E. To produce ionization
Not require physical contact
Interact via Coulomb force — act over a distance
Indirectly Ionizing radiation
Uncharged
Gamma rays and neutrons
Must come very close or physically contact
Can penetrate material and move through matter before it contacts an electron or nucleus —> directly ionizing radiation is produced
Characteristics of alpha particles
Most harmful
Travel in very short range
Have large mass
Only a hazard when inhaled
Characteristics of alpha decay
2 n+ 2 p= ejected
Occurs in very heavy elements bc they have more neutrons
lowers the Coulomb energy
Net electrical potential energy of the nucleus is reduced
Always produces particles with the same K.E.
Characteristics of beta decay
Mass number remains same
Atomic number increases in the negative beta decay
Atomic number decreases in the positive beta decay
Electron is emitted with an ANTİNEUTRİNO
Occurs in neutron rich isotopes
Beta-minus and beta-plus decay
During beta-minus decay
N—> p+ e + anti neutrino
During beta-plus decay
P—> n+ positron+ neutrino
Characteristics of beta particle
Can travel several meters in air
Can be stopped with a few sheets of aluminum foil, metal or plastic
Characteristics of gamma rays
Short wavelength photons
Emitted when a nucleus undergoes a transition from a higher to lower energy level
Half-lives usually very short
Very high energy
Characteristics of X-rays
Photons emitted from electron orbits
Lower energy then gamma rays
