lecture 1- ionizing radiation Flashcards
atomic mass (A)
number of protons plus neutrons
atomic number (Z)
number of protons
-same as # of electrons in a neural atom
the amount of energy required to remove an electron from its shell
binding energy
within a given atom, which shell electrons are more tightly bound
inner (K)
K>L>M
binding energy 2.
the electron binding energy is related to the
atomic number(Z)
higher Z (atomic #): more _____-> electrons are more ____ _____
more protons
electrons are more tightly bound
if the electrons = protons then it is a
neutral atom
this is the process of forming a positive and negative ion by removal of an electron from an neutral atom
ionization
if a neutral atom loses an electron it becomes a ____ ion, and the free electron becomes a ____ ion
positive
negative
how much external energy do we need to eject an electrol?
the same or more
the transmission of energy through space (vacuum) and matter
radiation
radiation may occur in two forms:
- wave theory
- quantum (particles) theory
this theory explains the propagation of radiation
wave theory
this theory explains the interaction of radiation with matter
quantum
distance between two successive crests
wavelength
number of wavelength passing a particular point in time
frequency
if there is high energy radiation:
1. frequency?
2. wavelength?
- high frequency
- short wavelength
if there is low energy radiation:
1. frequency?
2. wavelength?
- low frequency
- long wavelength
with electromagnetic radiation…
this does not have sufficient energy to eject an electron from the shells
non-ionizing
with electromagnetic radiation…
this has sufficient energy to eject an electron from the shells
ionizing
examples of non-ionizing
- radiowaves
- microwaves
- infrared radiation
- visible light
examples of ionizing
~ultraviolet
x-rays
gamma-rays
this considers radiation as small discrete bundles of energy called photons
- quantum theory of radiation: particles
each photon has energy, mass, and travels in ________ at the speed of light
straight lines
[!!!electrically charged!!! and neutrons/x-rays are not charged]
rate of loss of energy from a particle as it moves through matter
ionizing rate: linear energy transfer (LET)
LET (linear energy transfer) depends on
velocity, charge, and size
lower the velocity…
1. charge?
2. size?
3. LET?
higher charge
bigger size
greater LET
alpha particle:
x-ray:
high LET
low velocity
higher charge
bigger size
x-ray:
low LET
high velocity
lower charge
smaller size
weightless packages of pure energy (photons) without an electrical charge which travels in waves with a specific frequency and wavelength at the speed of light and are able to ionize matter
x-rays
list 7 properties of x-rays
- invisible, weightless, no electric charge
- travels in straight lines (diverge)
- travels at the speed of light
- highly penetrating (short wavelengths) LOW LET
- differentially absorbed by matter
- can ionize matter
- produce biological changes
when the transferred energy is not sufficient to overcome binding energy, e- is NOT ejected.
receiving e- is raised to higher energy level within the orbit. instantaneously gives up this excess energy and returns to ground level
excitation
minimum energy required to remove a proton from the nucleus
binding energy
