Chemistry Unit 2

Scale of atoms: Which EM radiation has wavelengths on the order of the sizes of atoms?

• A

• B

• C

• D

An MRI (magnetic resonance imaging) machine operates at a frequency of 30 kilohertz (kHz), what wavelength radiation does this

correspond to? kiloHz = 1000 Hz

• A

• B

• C

• D

• E

Absorption and Emission: Which one of these would produce an absorption spectrum (as opposed to emission)?

• A

• B

Here are the absorption and emission spectra for a particular element. Which of the two colors corresponds to the 2-->1 or 1-->2 level transitions?

• green

• yellow

Here are the absorption and emission spectra for a particular element. Which of the two colors corresponds to the 3-->1 or 1-->3 level transitions?

• green

• yellow

How much energy is required to

move an electron from n = 1 to n = 2

in a hydrogen atom? (1 electron volt (ev) = 1.6 × 101-19 J)

• 13.6eV

• 3.4eV

• 10.2eV

• 1.51eV

Which of the following transitions for an electron in a hydrogen atom would release the largest quantum of energy?

• n=3 to n=1

• n=4 to n=3

• n=2 to n=1

• n=3 to n=2

Can atoms of a particular element absorb (or emit) any wavelength of light?

• Yes

• No

Determine the wavelength of an X-ray with a frequency of 3.0 × 10^18

Hz. (c= 3.0 x 10^8 m/s). (answer in meters)

• 1.0 x 10^-10 m

• 9.0 x 10^26 m

• 9.0 x 10^-19 m

• 1.0 x 10^-1 m

• A

• B

• C

• D

• E