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1. Which of the following object does not emit light

Customer Question

1.     Which of the following object does not emit light?
A)     a candle flame
B)     the sun
C)     the moon
D)     a burning coal

2.     When an electric stove element is hot enough, it gives off a dull red glow. When it cools to the point that it longer glows, it will
A)     emit shorter wavelength radiation.
B)     emit the same wavelength as before, but with less energy.
C)     emit longer wavelength radiation.
D)     stop emitting radiation altogether.

3.     You are able to see non-luminous objects because light has undergone
A)     diffuse reflection.
B)     refraction.
C)     constructive interference.
D)     a change in speed.

4.     Interference can be most easily explained in terms of the
A)     ray model of light.
B)     particle model of light.
C)     wave model of light.
D)     photoelectric effect.

5.     Max Planck discovered that the blackbody radiation emitted by vibrating molecules
A)     was continuous, like a train of waves.
B)     was constant for all objects.
C)     varied greatly from one experiment to the next.
D)     appeared to come in multiples of certain fixed amounts.

6.     The photoelectric effect could not be adequately explained with a wave model of light because
A)     the energy of the electrons ejected from a metal varied directly with the intensity.
B)     the number of electrons ejected from a metal depended upon the intensity.
C)     the number of electrons ejected from a metal depended upon the wavelength.
D)     the energy of the ejected electrons did not depend upon the intensity.

7.     The sun appears reddish as it sets because
A)     the sun emits more radiation at longer wavelengths at sunset.
B)     more of the shorter, bluer wavelengths have been scattered away.
C)     the Doppler shift lowers the frequency as a given spot on the earth rotates away from the sun.
D)     more of the longer, redder wavelengths are scattered by the atmosphere.

8.     The image formed by a plane mirror is
A)     virtual.
B)     real.
C)     a result of diffuse reflection.
D)     smaller than the object.

9.     J.J. Thomson reasoned that cathode rays were really charged particles because
A)     a magnet deflected cathode rays.
B)     cathode rays formed only when the air was pumped out of a discharge tube.
C)     the properties of the cathode rays depended on the cathode material.
D)     the cathode rays were attracted to the anode.

10.     Robert Millikan discovered that
A)     the charge to mass ratio of electrons was constant.
B)     the electron carries the smallest unit of electrical charge.
C)     the oil droplets all carried the same amount of charge.
D)     the electrons contained most of the mass of an atom.

11.     The atomic number of an element is the number of
A)     protons.
B)     protons and neutrons.
C)     protons and electrons.
D)     all the particles in the atom.

12.     Neutral atoms of a given element have the same
A)     number of protons.
B)     atomic number.
C)     number of electrons.
D)     all of these are true.

13.     Atoms in an incandescent gas
A)     emit all frequencies of light in a continuous spectrum.
B)     emit different frequencies of light depending on its temperature.
C)     emit characteristic frequencies of light.
D)     absorb, rather than emit light.

14.     Niels Bohr's model of the hydrogen atom
A)     was controversial because it contradicted accepted principles of physics.
B)     held that electrons existed in allowed orbits and nowhere else.
C)     accounted for the observed spectrum in hydrogen.
D)     All of these are true.

15.     According to the quantum mechanical model, electrons exist in
A)     circular orbits
B)     elliptical orbits
C)     orbitals
D)     wavy orbits

16.     The proposal that matter, like light exhibits wave-like behavior was
A)     verified in diffraction experiments with a beam of electrons.
B)     never tested since it was known to be impossible.
C)     shown to be theoretically possible, but never verified by experiment.
D)     verified by physical measurements of a moving baseball.

17.     Evidence of a chemical reaction includes
A)     a color change.
B)     a change in temperature.
C)     the production of a gas.
D)     All of these.

18.     In an ionic compound, the metal
A)     usually forms a negative ion.
B)     takes the “-ide” ending.
C)     has a Greek prefix like mono, di or tri.
D)     is written first.

19.     The formation of an ionic bond
A)     involves a transfer of one or more electrons.
B)     results in a release of energy.
C)     helps atoms achieve a noble gas electron arrangement.
D)     All of these.

20.     Atoms that have eight valence electrons would tend to
A)     be very reactive.
B)     be inert.
C)     form positive ions.
D)     form negative ions.
Submitted: 6 years ago.
Category: Homework
Expert:  vidya suman replied 6 years ago.

Customer: replied 6 years ago.

I actually need to delete this post because I don't need the answers any longer. Could you tell me how I do that? I'm new to the site and can't figure out how to delete posts.


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