Exam 28: Atomic Physics: Part A

If a monochromatic light beam with quantum energy value of 4.0 eV is incident upon a photocell where the work function of the target metal is 1.60 eV,what is the maximum kinetic energy of ejected electrons?

Of photons of red,yellow,green,and blue light,which photons have the least energy?

Blue light (λ = 460 nm)is incident on a piece of potassium (W = 2.45 eV).What is the maximum kinetic energy of the ejected photoelectrons? (h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s,1 eV = 1.60 × 10−¹⁹ J,and 1 nm = 10−⁹ m)

Of the following energies for photons,which is the least energy that could result in photoelectron production if the work function is 1.60 eV?

Of the following photons,which has the lowest energy?

A light-emitting diode has a power output of 0.3 W.If 590 nm is the average wavelength of the source,about how many photons are emitted per second? (h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s,and 1 nm = 10−⁹ m)

If an electron has a measured wavelength of 1.20 × 10−¹⁰ m,what is its kinetic energy? (h = 6.63 × 10−³⁴ J⋅s,1 eV = 1.6 × 10−¹⁹ J,and m_e = 9.11 × 10−³¹ kg)

A detector absorbs 1.0 × 10⁹ photons of monochromatic light and their total energy is found to be 0.33 nJ.What is the wavelength associated with these photons? (h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s)

Sources of red,blue,and yellow light each emit light with a power of 50 mW.Which source emits the least photons per second?

A proton and an electron each have the same de Broglie wavelength.(i)Which has the lower speed,and (ii)which has the lower kinetic energy?

An electron microscope operates with electrons of kinetic energy 100 keV.What is the wavelength of these electrons? Assume this speed is not relativistic.(h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s,1 eV = 1.60 × 10−¹⁹ J,and m_e = 9.11 × 10−³¹ kg)

An electron and an alpha particle (a helium-4 nucleus)each have the same non-relativistic speed.Which has the greatest kinetic energy,and which has the shortest de Broglie wavelength?

What is the frequency of monochromatic light where the photon energy is 6.5 × 10−¹⁹ J? (h = 6.63 × 10−³⁴ J⋅s)

As the temperature of a radiation emitting blackbody becomes lower,what happens to the peak wavelength of the radiation?

Surface #1 has work function ,and when bombarded with photons of wavelength Emits photoelectrons with maximum energy )Surface #2 has work function ,and when bombarded by photons of wavelength Emits photoelectrons with maximum energy )If ,then which of the following must be true?

Light of wavelength 6.1 × 10−⁷ m has an energy of: (h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s)

What potential difference is needed to accelerate a proton from rest to give it a wavelength of 2.00 × 10^-12 m?

What is the wavelength of a monochromatic light beam,where the photon energy is 2.00 eV? (h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s,1 nm = 10−⁹ m,and 1 eV = 1.6 × 10−¹⁹ J)

What is the surface temperature of a distant star (which emits light as if it were a blackbody)where the peak wavelength is 456 nm? (Hint: The surface of the human body at 35° C has a peak wavelength of 9.41 μm).(1 nm = 10−⁹ m = 10^-3 μm)

According to Wien's displacement law,if the absolute temperature of a radiating blackbody is doubled,then the peak wavelength emitted will change by what factor?