Why is object 2 accelerating while object 1 remains stationary?

What would the difference of spectral lines emitted by hydrogen gas in distant galaxies which is normally found at a wavelength of 21 cm on earth, be observed at 21.1 centimeters?

Alice added sodium chloride to water and stirred the water for several minutes. alice is most likely trying to demonstrate that ionic compounds a. are hard. b. can dissolve. c. are clear. d. can melt.

Hydrogen atoms are excited by a laser to the =4n=4 state and then allowed to emit. what is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? 8 6 2 7 4 5 1 3 calculate the wavelength of the 4⟶14⟶1 transition. =λ=