Quiz | Early Quantum Theory

1

Which one of the following types of radiation has the highest wavelength?

Visible light

Infrared light

Ultraviolet light

X rays

Wavelength:

X rays < UV light < visible light < IR light

2

Which one of the following types of radiation has the highest frequency?

Infrared light

Ultraviolet light

Microwaves

Radio waves

Wavelength:

UV light < IR light < microwaves < radio waves

c = λv ⇒ frequency is inversely proportional to the wavelength

⇒ Frequency:

UV light > IR light > microwaves > radio waves

3

What is the energy of one photon with a wavelength of 2.25 x 10-2 m?

4.97 x 10-44 J

8.83 x 10-24 J

1.13 x 1023 J

2.01 x 1043 J

E = hcλ

h = Planck’s constant = 6.626 x 10-34 J.s

c = speed of light = 3.00 x 108 m.s-1

4

What is the frequency of radiation which has an energy of 1.52 x 106 J per mole of photons?

1.38 x 1063 Hz

2.29 x 1039 Hz

3.81 x 1015 Hz

2.63 x 10-16 Hz

E = nhv

n = number of photons = 1 mol = 6.022 x 1023 photons

5

Which statement below is incorrect regarding early quantum theory?

Bohr’s model of the atom accounts for the absorption and emission spectrum of hydrogen atom

Bohr’s model of the atom accounts for the Rydberg equation

Energy states in the hydrogen atom are quantized

None of the above

6

What is the energy of one electron in the second orbital of a hydrogen atom?

-5.45 x 10-19 J

5.45 x 10-19 J

-1.83 x 1018 J

1.83 x 1018 J

En- 2.1799 × 10-18n2

En = energy of the orbital n

n = number of the orbital = 2

7

According to the Bohr model for the hydrogen atom, how is the energy required to excite an electron from n=3 to n=4 compared to the energy required to excite an electron from n=2 to n=3?

Lower

Greater

Equal

Either equal or greater 

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