One of the lines of Hydrogen has a wavelength of 121.6 nm. If a cloud of Hydrogen gas is moving TOWARDS us at 200km/s, what will we detect?
a) An emission line in the cloud's spectrum with a wavelength shorter than 121.6 nm.
b) An emission line in the cloud's spectrum with a wavelength longer than 121.6 nm.
c) An emission line in the cloud's spectrum with a wavelength of exactly 121.6 nm.
d) This cloud will not emit a spectrum at all.
e) A continuous spectrum with an absorption line at exactly 121.6 nm.
Ans: a) An emission line in the cloud's spectrum with a wavelength shorter than 121.6 nm.
You might also like to view...
Today, the energy resource that supplies the United States with the greatest amount of electricity is
A) oil. B) coal. C) nuclear. D) hydroelectric. E) natural gas.
A building made with a steel structure is 650 m high on a winter day when the temperature is 0° F. How much taller (in cm) is the building when it is 100° F? (The linear expansion coefficient of steel is 11 × 10^-6 (°C)-1.)
a. 71 b. 36 c. 40 d. 46 e. 65
Country X's population is doubling every 10 years. What is its rate of population growth?
A) It is impossible to answer this without knowing country X's population. B) 2% per year C) 7% per year D) 10% per year E) 14% per year
The solar corona is much cooler than the Sun's surface; hence, we must wait for a total solar eclipse to glimpse it with the naked eye
Indicate whether the statement is true or false