A hydrogen atom is in its first excited state (n = 2). The linear momentum of the electron is (in kg m/s)
a. 3 1024
b. 2 1024
c. 1 1024
d. 4 1024
e. 3 1015
[Ques. 2] The motion of a Foucault pendulum proves that Earth is
a. rotating.
b. revolving.
c. precessing.
d. an oblate spheroid.
[Ques. 3] A Doppler red shift indicates
a. a shift toward higher frequencies.
b. a shift toward shorter wavelengths.
c. that a light source is approaching relative to the observer.
d. none of these.
[Ques. 4] An electron in a hydrogen atom makes a transition from the n = 3 to the n = 1 energy state. Determine the wavelength of the emitted photon (in nm).
a. 1006
b. 209
c. 306
d. 103
e. 821
[Ques. 5] Earth's axis is tilted ______________ degrees from the normal to the ecliptic plane.
a. zero
b. 90
c. 45
d. 23.5
[Ques. 6] The threshold of hearing is
a. 0 dB.
b. 140 dB.
c. 40 dB.
d. 110 dB.
e. 1 dB.
[Ques. 7] An electron in a hydrogen atom makes a transition from the n = 4 to the n = 3 energy state. Determine the energy (in eV) of the emitted photon.
a. 0.54
b. 0.66
c. 0.85
d. 1.51
e. 10.2
[Ques. 8] Retrograde motion of a planet refers to ______________ motion.
a. west-to-east
b. east-to-west
c. circular
d. elliptical
[Ques. 9] If a sound level increases by 40 dB, the intensity increases by a factor of ______________.
a. one hundred thousand
b. ten thousand
c. one thousand
d. one million
[Ques. 10] Light is emitted by hydrogen atoms in the visible range for a hydrogen atom. Its wavelength is 656 nm. What value of n is associated with the light? (RH = 1.097 107 m1)
a. 5
b. 2
c. 4
d. 3
e. 6
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