Solid argon has a density of 1650 kg/m3 . The atomic weight of argon is 40.0 . Assuming each atom occupies a cubical volume, what is the distance between the argon atoms?
[Ques. 2] The geocentric model of the solar system is attributed to
a. Kepler.
b. Brahe.
c. Copernicus.
d. Aristotle.
[Ques. 3] Which of the following sound frequencies lie(s) in the audible range?
a. 13 Hz
b. 5 kHz
c. 1 MHz
d. All of these
[Ques. 4] An LED emits light of wavelength 600 nm. What is its band gap?
a. 1.11 eV
b. 1.54 eV
c. 1.99 eV
d. 2.07 eV
e. 2.33 eV
[Ques. 5] The study of astronomy involves
a. space.
b. energy.
c. matter.
d. all of these.
[Ques. 6] Which of the following sound frequencies lie(s) in the audible range?
a. 26 Hz
b. 27 kHz
c. 1 MHz
d. All of these
[Ques. 7] Ellis and Randy are looking at a molecular absorption spectrum. The spectral lines appear to fall into two groups with a gap in the middle. Ellis says that this must be an absorption spectrum for transitions between the v = 0 and v = 1 vibrational states of a diatomic molecule. Randy says the gap in the middle must occur because a J = 0 transition is forbidden. Which one, if either, is correct, and why?
a. Ellis, because rotational levels are separated by greater energy differences than vibrational levels.
b. Randy, because rotational levels are separated by greater energy differences than vibrational levels.
c. Ellis, because the J = 0 transition is the most prominent spectral line in transitions between vibrational levels.
d. Neither, because rotational levels are separated by greater energies that vibrational levels and J = 0 transitions are not forbidden.
e. Both, because vibrational levels are separated by greater energy differences than rotational levels and J = 0 transitions are forbidden.
[Ques. 8] The first mate of a pirate ship shoots the noonday Sun with a sextant and measures the altitude to be 50o to the south on December 21 . The time on the ship's clock is 4 P.M. (GMT). What are the longitude and latitude of the ship?
[Ques. 9] Which of the following sound frequencies lie(s) in the audible range?
a. 23 Hz
b. 9 kHz
c. 3100 Hz
d. All of these
[Ques. 10] Because HF, hydrogen fluoride, is a covalent gaseous molecule at room temperature, we might reasonably expect that at room temperature HCl, hydrogen chloride, is
a. a covalent gaseous molecule.
b. a covalent solid.
c. a metallic gas.
d. a metallic solid.
e. an ionic solid.