Chapter 2 Flashcards
When x-rays pass through matter, which interaction results in x-rays being scattered in all directions 60 percent of the time?
C) Compton effect
The amount of energy deposited in the teeth or soft tissue by any type of radiation is called the
B) absorbed dose.
The unit used to measure the dose equivalent of radiation is the
B) sievert (Sv).
The sievert and rem are units of measurement for
C) the comparison of biological effects.
A weighting (qualifying) factor is used to determine which of the following?
B) Sievert
The wavelength determines the energy and penetrating power of the radiation. The longer the wavelength, the higher the energy of the radiation.
A) The first statement is true. The second statement is false.
Matter is defined as the ability to do work and overcome resistance.
FALSE
An atom is the smallest part of an element that still retains properties of that element.
TRUE
Electrons have a positive charge.
FALSE
The innermost electron shell in an atom is the K shell.
TRUE
Dental x-rays do not involve the use of radioactivity.
TRUE
X-rays travel at the speed of sound.
FALSE
Wavelength and frequency are directly related.
FALSE
X-rays make the materials they pass through radioactive.
FALSE
The photoelectric effect is an all-or-nothing energy loss.
TRUE
The Compton effect causes x-rays to be scattered in all directions.
TRUE
The number of electrons in the nucleus of an element determines its atomic number.
FALSE
Background radiation includes cosmic rays from outer space, naturally occurring radiation from the earth, and radiation from radioactive materials.
TRUE
Kinetic energy is the internal energy within the atom that holds its components together.
FALSE
The total number of protons in the nucleus of an atom determines the atomic number.
TRUE
Energy that travels in a different direction than that of the original x-ray is collectively called ‘secondary radiation.’
TRUE
The majority of x-rays produced by dental x-ray machines are formed by general (bremsstrahlung) radiation.
TRUE
The electromagnetic spectrum arranges energy types by decay rates.
FALSE
X-rays of high energy and extremely short wavelengths are classified as hard radiation.
TRUE
Ionizing radiation is energy that is capable of producing ions.
TRUE
Electromagnetic radiation is propelled through space as both particles and waves.
TRUE
What is defined as anything that occupies space and has mass?
Matter.
What are the positively charged particles in the nucleus of an atom called?
Protons.
What is the term for atoms that have gained or lost electrons and electrical neutrality?
Ions.
What is the name of the process in which unstable elements undergo spontaneous decay in order to become stable?
Radioactivity.
What is the term for bundles of energy that travel through space at the speed of light?
Photons.
What is the speed of a wave called?
Velocity.
When radiation has great penetrating power, what is it called?
Hard radiation.
Should you wait 30 seconds after making an exposure before entering the room?
No.
People living on the Colorado plateau receive a higher dose of what type of radiation than people living in Philadelphia?
Background.
One gray equals how many rads?
100.
