if we continue heating piece initially room temperature metal dark room what will be its fir

If we continue heating a piece of initially room-temperature metal in a dark room, what will be its first visible color? 1. There will be no color at all. 2. Red 3. Violet 4. White 002 10.0 points The temperature of your skin is approxi- mately 37 C. What is the wavelength at which the peak occurs in the radiation emitted from your skin? Answer in units of nm 003 10.0 points A quantum of electromagnetic radiation has an energy of 0.83 keV. What is its frequency? Planck’s constant is 6.63 × 10−34 J · s. Answer in units of Hz 004 10.0 points An X-ray has a wavelength of 0.0238 nm. What is the energy of this X-ray? The speed of light is 2.99792 × 108 m/s and Planck’s constant is 6.62607 × 10−34 J · s. Answer in units of eV 005 10.0 points For the following types radio waves infared radiation visible light ultraviolet radiation gamma radiation of electromagnetic radiation, how do the wavelength, frequency, and photon energy change as one goes from the top of the list to the bottom? Wavelength Frequency Photon Energy 1. Increases Decreases Increases 2. Increases Increases Increases 3. Decreases Decreases Increases 4. Increases Decreases Decreases 5. Decreases Increases Increases 006 10.0 points In the photoelectric effect, the maximum speed of the electrons emitted by a metal sur- face when it is illuminated by light depends on which of the following? I) Intensity of the light II) Frequency of the light III) Nature of the photoelectric surface 1. I only 2. II and III only 3. III only 4. I, II, and III 5. I and II only 007 10.0 points The light intensity incident on a metallic sur- face with a work function of 1.1 eV produces photoeletrons with a maximum kinetic energy of 2.65 eV. If the frequency of the light is doubled, what is the maximum kinetic energy of the photoeletrons? Answer in units of eV 008 10.0 points The photoelectric effect experiment was sig- nificant because 1. it showed us how to make an instrument to detect light by converting photons into brown (cb42578) – Homework 12 – appartaim – (20541) 2 electrons, ultimately leading to the invention of the television camera. 2. it demonstrated the existence of quan- tized states in atoms. 3. it proved that atoms cannot exist if the rules of classical physics were obeyed on the atomic scale. 4. it led to the development of the Heisen- berg Uncertainty Principle, a revolutionary development that forced us to abandon the idea of determinacy at the atomic scale and accept that all we can know are the probabil- ities of future outcomes. 5. it required us to accept the fact that light can behave like particles, in contrast to the teachings of classical physics. 009 (part 1 of 2) 10.0 points The work function for potassium is 2.24 eV. If potassium metal is illuminated with light of wavelength 320 nm, find the maximum kinetic energy of the photoelectrons. The speed of light is 3 × 108 m/s and Planck’s constant is 6.62607 × 10−34 J · s . Answer in units of eV 010 (part 2 of 2) 10.0 points Find the cutoff wavelength. Answer in units of nm 011 10.0 points Calculate the de Broglie wavelength for a pro- ton moving with a speed of 3.2 × 106 m/s. The mass of a proton is 1.67262 × 10−27 kg and Planck’s constant is 6.62607 × 10−34 J · s. Answer in units of m 012 10.0 points At the time of Rutherford’s gold leaf experi- ment, scientists knew that negatively charged electrons existed within the atom, but they did not know where the positive charge resided. What information about the positive charge was provided by Rutherford’s exper- iment? 1. The positive charge must be concentrated in a small core (the atomic nucleus). 2. The positive charge can freely move within the atom. 3. There is no positive charge associated with an atom. 4. The positive charge is spread throughout the atom. 013 10.0 points In the Bohr model of the atom, the postulate stating that the orbital angular momentum of the electron is quantized can be interpreted in which of the following ways? 1. The atom is composed of a small, posi- tively charged nucleus orbited by electrons. 2. An integral number of electron wave- lengths must fit into the electron’s circular orbit. 3. An electron has spin of 1 2 . 4. Only one electron can exist in each possi- ble electron state. 5. An incident photon is completely ab- sorbed when it causes an electron to move to a higher energy state. 014 (part 1 of 6) 10.0 points A hydrogen atom is in the excited state (n = 3). Using the Bohr theory of the atom, find the radius of the orbit. The value of ¯h is 1.05 × 10−34 J · s . Answer in units of nm 015 (part 2 of 6) 10.0 points Find the linear momentum of the electron. Coulomb’s constant is 8.99 × 109 N · m2/C2 . Answer in units of kg · m/