Explain why it is expected that narrow lines of light are observed instead of a continuous rainbow at all wavelengths in the atomic emission spectra. You may find it helpful to refer to Bohr's model in your answer.

Lines in the spectrum were due to transitions in which an electron moved from a higher-energy orbit with a larger radius to a lower-energy orbit with smaller radius. ... Transitions from an excited state to a lower-energy state resulted in the emission of light with only a limited number of wavelengths.

Explanation:

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b