Chapter 30
How does the difference in energy between energy levels relate to the energy of the photon that is emitted by a transition between those levels?
The energy of the photon is equal to the difference in energy between the energy levels.
How can a hydrogen atom, which has only one electron, have so many spectral lines?
The many spectral lines from the element hydrogen are the result of the many energy states the single electron can occupy when excited.
What is the evidence for the claim that iron exists in the relatively cool outer layer of the Sun?
When a spectrum of the Sun is compared with the spectrum of the element iron, the iron lines overlap and perfectly match certain Fraunhofer lines. This is evidence for the presence of iron in the Sun.
How does an absorption spectrum differ in appearance from an emission spectrum?
an emission spectrum consists of bright lines against a dark background, whereas an absorption spectrum consists of dark line against a bright rainbow background.
How do the surface temperatures of reddish, bluish, and whitish stars compare?
bluish star is the hottest, then white and red
How is the energy of a photon related to its vibrational frequency?
the energy is proportional to the frequency
Since every object has some temperature, every object radiates energy. Why, then, can't we see objects in the dark?
we can't see them in the dark as they do not emit energy. the reason we see them in light is because light doesn't go through them. it hits it, and reflects off. if it went through, it would be invisible.
What is a spectroscope, and what does it accomplish
A spectroscope displays the spectrum of light as brightness versus wavelength.
Does atomic excitation occur in solids as well as in gases? How does the radiant energy from an incandescent solid differ from the radiant energy emitted by an excited gas?
Atomic excitation occurs in solids, liquids, and gases.
Which has the higher frequency: red or blue light? Which has the greater energy per photon: red or blue light?
Blue light, blue light
When a gas glows, discrete colors are emitted. When a solid glows, the colors are smudged. Why?
Emitting electrons interact with nearby neighboring atoms in a solid. In a gas, there are few nearby atoms.
Green light is emitted when electrons in a substance make a particular energy-level transition. If blue light were instead emitted from the same substance, would it correspond to a greater or lesser change of energy in the atom?
Greater because blue is higher than green
In a neon tube, what occurs immediately after an atom is excited
It de-excites and emits light. Electrons are boiled off electrodes at tube ends, jostling at high speeds by AC voltage; smashing boosts orbital e- into higher energy levels
Consider just four of the energy levels in a certain atom, as shown in the diagram below. How many spectral lines will result from all possible transitions among these levels? Which transition corresponds to the highest-frequency light emitted? To the lowest-frequency light emitted?
Six transitions are possible. The highest-frequency transition is from quantum level 4 to level 1. The lowest-frequency transition is from quantum level 4 to level 3
