Electromagnetic Radiation

a type of heat radiation; the infrared light in sunlight, for example, is what makes the sunlight feel warm upon one's skin.

infrared light

what is the frequency of a wave if only one-tenth of it goes by in 1 second?

0.10 cycle

how is a hertz (Hz) defined?

1 cycle per second

based upon the inverse square law, how will the intensity of light change as the distance increases from 1m to 4m from the source?

1/16 as intense

which of the following is the speed of light?

300 million m/sec

if a wavelength of electromagnetic energy is 1/2 m, what is the frequency?

600 MHz

if light photons are stopped by a substance, the light is said to be:

absorbed

a particle that has two protons and two neutrons bound together, but no electrons.

alpha particle

which of the following has the longest wavelength?

am radio

the height of a wave is called:

amplitude

the height of a wave. a wave with a large amplitude is generally stronger than a wave with a small amplitude.

amplitude

the condition of light when some of the photons are absorbed but some are transmitted through a substance.

attenuated

what happens when an electron falls back into its normal lower shell? a. it emits energy b. a photon is released c. the atom returns to its normal state d. all of the above

d. all of the above

which of the following have photons? a. x-rays b. gamma rays c. visible light d. all of the above

d. all of the above

which of the following is true of all electromagnetic energy? a. it has photons b. it has varying levels of energy c. it moves at the speed of light d. all of the above

d. all of the above

electromagnetic energy is a combination of:

electric and magnetic fields

what is the range of wavelengths called that includes x-rays, radio waves, and visible light?

electromagnetic spectrum

x-ray originate in:

electron shells

as photons collide with body tissue, what part of body atoms can be broken from molecules?

electrons

in electromagnetic energy, what is vibrating?

energy itself

x-rays and gamma rays are different from light because they have:

enough energy to knock electrons out of atoms

the number of waves that go by in 1 second is called:

frequency

the number of waves that go by in a second.

frequency

x-rays can have differing amounts of energy because the amount of energy a photon has is proportional to its:

frequency

the amount of energy carried in a wave increases as the:

frequency increases

a type of electromagnetic radiation at the high end of the spectrum with a frequency greater than visible light and ultraviolet light.

gamma ray

the SI unit of measurement for frequency (abbreviated Hz)

hertz

what is the SI unit of measurement for frequency?

hertz

what occurs when something makes an electron jump to a higher shell?

it gains energy

which of the following is not true of all electromagnetic energy?

it has a constant frequency

A characteristic of photons is that they all have:

no mass

the property of a substance that totally absorbs light rays.

opaque

a particle of energy that has no mass; emitted as light or another form of electromagnetic energy.

photon

photoelectric cells convert sunlight into electricity when struck by a steady stream of:

photons

the property of a substance that allows x-rays to partially pass through it.

radiolucent

the property of a substance that does not allow x-rays to pass through it

radiopaque

x-rays cannot pass through lead because it is:

radiopaque

the bending of light photons as they pass through one clear medium to another.

refraction

the bending of light rays through a prism is called:

refraction

the wave form of electromagnetic energy, the wave having regular characteristics such as a constant amplitude and wavelength.

sine wave

x-rays are generally attenuated by:

soft tissue

approximately 3x10^8 m/sec, or 300 million meters per second. all electromagnetic radiation travels at the same velocity through space.

speed of light

the longer the wavelength:

the lower the frequency

gamma rays originate in:

the nucleus

frequency is determined by:

the number of waves in 1 second

the property of a substance that partially absorbs, or attenuates, light rays.

translucent

the state of light photons that have passed through a substance such as air, clear glass, or the near vacuum of space

transmitted

electromagnetic energy in a vacuum would normally:

travel in a straight line

as an unstable atom of a radioactive element naturally decays into a more stable state, it emits at that moment of decay a photon of energy and:

two protons and two neutrons

energy at a higher frequency that can interact with molecules in one's skin and cause sunburn or, over a long term, skin cancer.

ultraviolet light

which of the following has the highest frequency?

ultraviolet light

waves in the electromagnetic spectrum all travel at the same ___________, the speed of light, or 300 million meters per second.

velocity

what does frequency times wavelength equal?

velocity

which of the following has the shortest wavelength?

visible light

a property of energy created by the vibrations of photons. it can be compared to a ripple that moves water molecules up and down on the surface of a pond.

wave

the length of one wave, measured from the top of one wave to the top of the next. ________=velocity/frequency

wavelength

the measurement from the top of one wave to the top of the next is called:

wavelength

what does velocity divided by frequency equal?

wavelength

frequency rises as the:

wavelength shortens