Ch 2. Dental Radiation Physics

Which electrons have the greatest binding energy?

• N-shell

• M-shell

• L-shell

• K-shell

Answer explanation

The K shell electron is located closest to the nucleus and has the highest energy level and the greatest binding energy. The M, N, and L shell electrons are located farther from the nucleus.

What type of electrical charge does the electron carry?

• positive

• negative

• no charge

• positive or negative

Answer explanation

An electron is a negatively charged particle.

Which term describes two or more atoms that are joined by chemical bonds?

• ion

• ion pair

• molecule

• proton

Answer explanation

a. An ion is an atom that gains or loses an electron.

b. An ion pair is formed when an electron is removed from an atom.

d. A proton is a particle in the nucleus that carries a positive electrical charge.

Tags

NGSS.HS-PS1-4

Which statement describes ionization?

• atom without a nucleus

• atom that loses an electron

• atom with equal numbers of protons and electrons

• none of the above

Answer explanation

Ionization is described as the production of ions when an atom loses an electron.

Which term describes the process by which unstable atoms undergo spontaneous disintegration in an effort to attain a more balanced nuclear state?

• radiation

• radioactivity

• ionization

• ionizing radiation

Answer explanation

a. Radiation is the propagation of energy through space in the form of waves or particles.

c. Ionization is the production of ions when an atom loses an electron.

d. Ionizing radiation is radiation that is capable of producing ions.

Tags

NGSS.HS-PS1-8

Which is not a type of particulate radiation?

• alpha particles

• beta particles

• protons

• nucleons

Answer explanation

Alpha particles, beta particles, and protons possess mass and are considered particulate radiation.

Tags

NGSS.HS-PS1-8

Which is not a type of electromagnetic radiation?

• electrons

• radar waves

• microwaves

• x-rays

Answer explanation

Radar waves, microwaves, and x-rays are human-made or occur naturally and are arranged according to their energy level in the electromagnetic spectrum.

Which statement is incorrect?

• Velocity is the speed of a wave

• Wavelength is the distance between waves

• Frequency is the number of wavelengths that pass a given point in a certain amount of time

• Frequency and wavelength are inversely related

Answer explanation

Wavelength is defined as the distance between the crest of one wave and the crest of the next wave.

Tags

NGSS.HS-PS4-1

Which statement is incorrect?

• x-rays travel at the speed of sound

• x-rays have no charge

• x-rays cannot be focused to a point

• x-rays cause ionization

Answer explanation

X-rays travel at the speed of light.

Tags

NGSS.HS-PS4-3

NGSS.HS-PS4-4

Which statement is correct?

• x-rays are a form of electromagnetic radiation; visible light is not

• x-rays have more energy than does visible light

• x-rays have a longer wavelength than does visible light

• x-rays travel more slowly than visible light

Answer explanation

a. X-rays and visible light are both forms of electromagnetic radiation.

c. X-rays have a shorter wavelength than visible light.

d. X-rays travel at the speed of light.

Tags

NGSS.HS-PS4-1