A metal with a threshold frequency of 1.62×1015 s−1s−1 emits an electron with a velocity of 6.42×105 m/sm/s when radiation of 1.89×1015 s−1s−1 strikes the metal. Calculate the mass of the electron.

What wavelength of electromagnetic radiation corresponds to a frequency of 7.76 109 s1 ? Note that Plancks constant is 6.63 1034 J s, and the speed of light is 3.00 108 m/s.

The space probe Pioneer 11 was launched April 5, 1973, and reached Jupiter in December 1974, traveling a distance of 998 million km. How long did it take an electromagnetic signal to travel to Earth from Pioneer 11 when it was near Jupiter?

Light with a wavelength of 405 nm fell on a strontium surface, and electrons were ejected. If the speed of an ejected electron is 3.36 105 m/s, what energy was expended in removing the electron from the metal? Express the answer in joules (per electron) and in kilojoules per mole (of electrons).

6.101 Laser welding is a technique in which a tightly focused laser beam is used to deposit enough energy to weld metal parts together. Because the entire process can be automated, it is commonly used in many large-scale industries, including the manufacture of automobiles. In order to achieve the desired weld quality, the steel parts being joined must absorb energy at a rate of about 104 W/mm2. (Recall that 1 W = 1 J/s.) A particular laser welding system employs a Nd:YAG laser operating at a wavelength of 1.06m ; at this wavelength steel will absorb about 80% of the incident photons. If the laser beam is focused to illuminate a circular spot with a diameter of 0.02 inch, what is the minimum power (in watts) that the laser must emit to reach the 104 W/mm2 threshold? How many photons per second does this correspond to? (For simplicity, assume that the energy from the laser does not penetrate into the metal to any significant depth.)

As the weapons officer aboard the Srarship Chemistry, it is your duty to configure a photon torpedo to remove an electron from the outer hull of an enemy vessel. You know that the work function (the binding energy of the electron) of the hull of the enemy ship is 7.52 1019 J. a. What wavelength does your photon torpedo need to be to eject an electron? b. You find an extra photon torpedo with a wavelength of 259 nm and fire it at the enemy vessel. Does this photon torpedo do any damage to the ship (does it eject an electron)? c. If the hull of the enemy vessel is made of the element with an electron configura tion of [Ar]4s13d10, what metal is this?

In X-ray fluorescence spectroscopy, a material can be analyzed for its constituent elements by radiating the material with short-wavelength X rays, which induce the atoms to emit longer-wavelength X rays characteristic of those atoms. Tungsten, for example, emits characteristic X rays of wavelength 0.1476 nm. If an electron has an equivalent wavelength, what is its kinetic energy?

An FM radio station broadcasts at a frequency of 101.3 MHz. What is the wavelength, in meters and nanometers, of this radiation?

An atom emits yellow light when an electron makes the transition from the n = 5 to the n = 1 level. In separate experiments, suppose you bombarded the n = 1 level of this atom with red light, yellow light (obtained from the previous emission), and blue light. In which experiment or experiments would the electron be promoted to the n = 5 level?

Investigating Energy Levels Consider the hypothetical atom X that has one electron like the H atom but has different energy levels. The energies of an electron in an X atom are described by the equation E=RHn3 where RH is the same as for hydrogen (2.179 1018 J). Answer the following questions, without calculating energy values. a How would the ground-state energy levels of X and H compare? b Would the energy of an electron in the n = 2 level of H be higher or lower than that of an electron in the n = 2 level of X? Explain your answer. c How do the spacings of the energy levels of X and H compare? d Which would involve the emission of a higher frequency of light, the transition of an electron in an H atom from the n = 5 to the n = 3 level or a similar transition in an X atom? e Which atom, X or H, would require more energy to completely remove its electron? f A photon corresponding to a particular frequency of blue light produces a transition from the n = 2 to the n = 5 level of a hydrogen atom. Could this photon produce the same transition (n = 12 to n = 5) in an atom of X? Explain.