How are we able to determine the chemical composition and temperature of any visible object?
What will be an ideal response?
When an electron moves from one energy level to another (makes a transition) in an atom of a given element, it produces a photon of light at a wavelength that is unique to that transition for that element. If this spectral line with this wavelength is observed then, we know that it must have been produced by that element. Which transitions occur are determined largely by the temperature of the gas; for instance, hydrogen shows up best at 10,000 K, while helium lines require even higher temperatures.
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Kepler's Third law relates a planet's orbital period and its average distance from the Sun (p2 = a3 ). If a new comet were discovered with an average distance from the Sun of 100 AU, its period would be
A) 1000 years. B) 10,000 years. C) 150 years. D) 1 million years. E) not enough information to say.
Which of the following is the best description of how a fluorescent bulb works?
A) Electrons flowing through the bulb get heated up within the bulb, and these electrons emit light. B) A gas flows from one end of the bulb to the other, and the gas atoms are energized by the electric field which causes the atoms to emit light. C) Electrons flow through the bulb, causing a chemical reaction in the gas atoms inside the bulb, which causes these atoms to emit light. D) A gas fills the bulb and when the gas atoms strike the walls of the bulb the material in the wall emits light. E) Electrons flow from one end of the bulb to the other, hitting gas atoms and causing them to emit light.
For an electron in the M (n = 3 ) shell, find (a) the largest possible orbital angular momentum it can have, and (b) the smallest possible orbital angular momentum it can have
Express your answers in SI units, and for each case indicate the subshell (s, p, d, ...) of the electron. (h = 6.626 × 10-34 J ? s)
A 2.0-kg mass in the xy plane is moving in the negative x direction at 3.0 m/s along the line y = 5.0 m. As the mass passes across the y axis (i.e., passing the point (x, y = 0, 5.0 m)), what is its angular momentum with respect to the z axis?
a. 30 SI units c. -30 SI units b. 150 SI units d. -150 SI units