Question 1

A light emitting diode (L.E.D.)emits photons with an energy of  J.What is the energy per mole of photons emitted?
A)  J/mol
B)  J/mol
C)  J/mol
D)  J/mol
E)  J/mol

Accepted Answer

A

Question 2

A device operates at a frequency of Hz.What is the wavelength of this radiation? A) 667 nm B) nm C) nm D) 0.0895nm E) nm

Accepted Answer

A

Question 3

What is the wavelength of a photon having a frequency of 11.7 THz? (1 THz = 10¹⁵ Hz) A) 0.0390nm B) 7.76 $\times$ 10^-24nm C) 2.33 $\times$ 10^-15nm D) 25.6nm E) 2.56 $\times$ 10¹⁶nm

Accepted Answer

D

Question 4

According to experiments concerned with the photoelectric effect,which of the following will increase the kinetic energy of an electron ejected from a metal surface?
1)increasing the wavelength of the light striking the surface
2)increasing the frequency of the light striking the surface
3)increasing the number of photons of light striking the surface
A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 1,2,and 3

Accepted Answer

According to the photoelectric effect, the kinetic energy of an electron is determined by the frequency of the light striking the surface, not the wavelength or the number of photons. Increasing the frequency of the light will increase the kinetic energy of the ejected electron, while increasing the wavelength or number of photons will not have any significant effect on the kinetic energy. Therefore, choice 2 is the correct answer.

Question 5

What is the energy of a photon of electromagnetic radiation with a wavelength of 451.7 nm?
A)  J
B)  J
C)  J
D)  J
E)  J

Accepted Answer

The answer of What is the energy of a photon...

Question 6

Which of the following statements is/are CORRECT?
1)FM radio waves have longer wavelengths than visible radiation and AM radio waves have shorter wavelengths than visible radiation.
2)Magnetic resonance imaging (MRI)uses a mixture of x-rays and gamma rays.
3)Exposure to ultraviolet (UV)radiation can lead to sunburns.
A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Accepted Answer

1) This statement is incorrect. FM radio waves have shorter wavelengths than visible radiation while AM radio waves have longer wavelengths than visible radiation.
2) This statement is incorrect. Magnetic resonance imaging (MRI) does not use x-rays or gamma rays. It uses a combination of strong magnets and radio waves.
3) This statement is correct. Exposure to UV radiation can damage the skin and cause sunburns.

Question 7

Which of the following ranks regions of the electromagnetic spectrum in proper order from highest to lowest frequency.
A) radio > ultraviolet> x-rays > visible > microwaves
B) x-rays > ultraviolet > visible > microwaves> radio
C) microwaves > x-rays > ultraviolet > visible > radio
D) ultraviolet > x-rays > microwaves > visible > radio
E) visible > microwaves > radio > ultraviolet > x-rays

Accepted Answer

The electromagnetic spectrum is ordered by frequency as follows: gamma rays, x-rays, ultraviolet, visible, infrared, microwaves, and radio waves.

Question 8

What is the energy per mole of photons of light with a wavelength of 976.9 nm?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of What is the energy per mole of...

Question 9

Which of the following regions of the electromagnetic spectrum has the lowest frequency?
A) x-ray
B) gamma ray
C) ultraviolet
D) infrared
E) visible

Accepted Answer

Infrared radiation has the lowest frequency among the given options. The frequency increases in the order of radio waves, microwaves, infrared, visible, ultraviolet, x-ray, and gamma ray, with radio waves having the lowest frequency and gamma rays having the highest frequency.

Question 10

A red laser pointer emits light at a wavelength of 488 nm.If the laser emits 7.5 $\times$ 10^-4 J of energy per second in the form of visible radiation,how many photons per second are emitted from the laser? A) 4.1 $\times$ 10^-19 photons/sec B) 5.4 $\times$ 10^-16 photons/sec C) 8.9 $\times$ 10¹⁴ photons/sec D) 1.8 $\times$ 10¹⁵ photons/sec E) 2.5 $\times$ 10¹⁸ photons/sec

Accepted Answer

The energy of one photon is calculated using E = hc/λ. For λ = 488 nm, E ≈ 4.07 x 10^-19 J/photon. The number of photons per second is the total energy per second divided by the energy per photon: (7.5 x 10^-4 J/s) / (4.07 x 10^-19 J/photon) ≈ 1.8 x 10^15 photons/sec.

Question 11

What is the frequency of gamma ray radiation that has a wavelength of 11.4 pm? A) 3.80 $\times$ 10^-20 s^-1 B) 1.74 $\times$ 10^-14 s^-1 C) 2.63 $\times$ 10⁷ s^-1 D) 3.42 $\times$ 10⁹ s^-1 E) 2.63 $\times$ 10¹⁹ s^-1

Accepted Answer

The frequency $ f $ can be calculated using the formula $ f = \frac{c}{\lambda} $, where $ c $ is the speed of light ($3 \times 10^8$ m/s) and $ \lambda $ is the wavelength (11.4 pm = 11.4 $\times$ 10^-12 m). This gives $ f = \frac{3 \times 10^8}{11.4 \times 10^{-12}} \approx 2.63 \times 10^{19} $ s^-1.

Question 12

A device emits light at 761.7 nm.What is the frequency of this radiation? A) 3.94 $\times$ 10^-4Hz B) 1.15 $\times$ 10²⁷Hz C) 3.94 $\times$ 10¹⁴Hz D) 2.61 $\times$ 10^-37Hz E) 2.61 $\times$ 10^-19Hz

Accepted Answer

The answer of A device emits light at 761.7 nm.What...

Question 13

The ____ of a photon of light is ____ proportional to its frequency and ____ proportional to its wavelength.
A) energy,directly,inversely
B) energy,inversely,directly
C) velocity,directly,inversely
D) intensity,inversely,directly
E) amplitude,directly,inversely

Accepted Answer

According to the equation E=hf, where E is the energy of a photon, h is Planck's constant, and f is the frequency of the photon, the energy of a photon is directly proportional to its frequency. Additionally, the speed of light in a vacuum is constant, so the product of frequency and wavelength must be equal to the speed of light. Therefore, as frequency increases, wavelength decreases, meaning that energy is inversely proportional to wavelength.

Question 14

What is the wavelength of a photon that has an energy of  J?
A)  nm
B)  nm
C) 0.842 nm
D)  nm
E)  nm

Accepted Answer

The answer of What is the wavelength of a photon...

Question 15

If the energy of 1.00 mole of photons is 245 kJ,what is the wavelength of the light?
A) 122 nm
B) 488 nm
C) 1220 nm
D) 787 nm
E) 811 nm

Accepted Answer

The energy of 1.00 mole of photons can be calculated using Avogadro's number and the equation E = hc/λ, where h is Planck's constant and c is the speed of light.

245 kJ/mol = (6.022 x 10^23 photons/mol) x (h x c/λ)

Solving for λ, we get:
λ = (h x c)/(245 kJ/mol / 6.022 x 10^23 photons/mol) = 488 nm

Question 16

What is the energy of a photon of electromagnetic radiation with a frequency of  Hz?
A)  J
B)  J
C)  J
D)  J
E)  J

Accepted Answer

The answer of What is the energy of a photon...

Question 17

What is the energy per mole of photons of light with a frequency of 
A) 
B) 
C) 
D) 
E)

Accepted Answer

The energy of a photon is given by the equation E = hf, where h is Planck's constant (6.626 x 10^-34 J.s) and f is the frequency of the light. Substituting the given frequency (11ea8937_ab5f_a4a8_a16d_5f0d2e8a1430_TB4499_11) into this equation gives us:

E = (6.626 x 10^-34 J.s) x (2.714 x 10^14 Hz) = 1.799 x 10^-19 J/photon

To convert this to energy per mole of photons, we need to multiply by Avogadro's number (6.022 x 10^23). Therefore:

Energy per mole = (1.799 x 10^-19 J/photon) x (6.022 x 10^23 photons/mol)

= 1.083 x 10^5 J/mol

Choice B (11ea8937_ab5f_a4aa_a16d_d9a81eaf4375_TB4499_11) is the only option that matches this value.

Question 18

What is the binding energy of an electron in a photosensitive metal (in kJ/mol)if the longest wavelength of light that can eject electrons from the metal is 205 nm? A) 279 kJ/mol B) 584 kJ/mol C) 792 kJ/mol D) 1.71 $\times$ 10¹⁹ kJ/mol E) 5.84 $\times$ 10^-20 kJ/mol

Accepted Answer

We can use the equation E=h*c/λ, where h is Planck's constant, c is the speed of light, and λ is the wavelength of light. 
First, we need to convert the longest wavelength to meters:
205 nm = 205*10^-9 m
Then, we can plug in the values and solve for the energy of the photon:
E = (6.626*10^-34 J*s)(3.00*10^8 m/s)/(205*10^-9 m) = 9.651*10^-19 J
Finally, we can convert the energy to kJ/mol using Avogadro's constant:
9.651*10^-19 J/mol * 1 kJ/1000 J * 6.022*10^23 mol^-1 = 5.84 kJ/mol
Therefore, the answer is B) 584 kJ/mol.

Question 19

If a cordless phone operates at a frequency of 9.00 $\times$ 10⁸ s^-1.What is the wavelength of this radiation? A) 0.333 m B) 1.99 $\times$ 10^-25 m C) 3.33 $\times$ 10^-9 m D) 3.71 $\times$ 10^-18 m E) 2.70 $\times$ 10¹⁷ m

Accepted Answer

The answer of If a cordless phone operates at a...

Question 20

Which of the following colors of visible light has the highest frequency?
A) green
B) orange
C) red
D) yellow
E) blue

Accepted Answer

The frequency of visible light is inversely proportional to its wavelength, and blue light has the shortest wavelength among the given options, thereby making it the one with the highest frequency.

Quiz 7: The Structure of Atoms

A light emitting diode (L.E.D.) emits photons with an energy of J.What is the energy per mole of photons emitted?

A device operates at a frequency of Hz.What is the wavelength of this radiation?

What is the wavelength of a photon having a frequency of 11.7 THz? (1 THz = 10¹⁵ Hz)

What is the energy of a photon of electromagnetic radiation with a wavelength of 451.7 nm?

Which of the following ranks regions of the electromagnetic spectrum in proper order from highest to lowest frequency.

What is the energy per mole of photons of light with a wavelength of 976.9 nm?

Which of the following regions of the electromagnetic spectrum has the lowest frequency?

A red laser pointer emits light at a wavelength of 488 nm.If the laser emits 7.5 $\times$ 10^-4 J of energy per second in the form of visible radiation,how many photons per second are emitted from the laser?

What is the frequency of gamma ray radiation that has a wavelength of 11.4 pm?

A device emits light at 761.7 nm.What is the frequency of this radiation?

The of a photon of light is proportional to its frequency and proportional to its wavelength.

What is the wavelength of a photon that has an energy of J?

If the energy of 1.00 mole of photons is 245 kJ,what is the wavelength of the light?

What is the energy of a photon of electromagnetic radiation with a frequency of Hz?

What is the energy per mole of photons of light with a frequency of

What is the binding energy of an electron in a photosensitive metal (in kJ/mol) if the longest wavelength of light that can eject electrons from the metal is 205 nm?

If a cordless phone operates at a frequency of 9.00 $\times$ 10⁸ s^-1.What is the wavelength of this radiation?

Which of the following colors of visible light has the highest frequency?