SCI 190 Ch 30 HW

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.

In the diagram, the energy difference between states A and B is twice the energy difference between states B and C. In a transition (quantum jump) from C to B, an elec-tron emits a photon of wavelength 600 nm. (a) What is the wavelength emitted when the photon jumps from B to A? (b) When it jumps from C to A?

a) frequency is half the wavelength b) frequency is 1/3 the wavelength

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

How do the surface temperatures of reddish, bluish, and whitish stars compare?

he temperature is lowest for reddish stars, medium for whitish stars, and hottest for bluish.

In a neon tube, what occurs immediately after an atom is excited?

it de-excites and emits light

If we double the frequency of light, we double the energy of each of its photons. If we instead double the wave-length of light, what happens to the photon energy?

it decreases by half

Since every object has some temperature, every object radiates energy. Why, then, can't we see objects in the dark?

our eyes cannot see infrared rays

How is the energy of a photon related to its vibrational frequency?

the energy is proportional to the frequency

How can a hydrogen atom, which has only one electron, have so many spectral lines?

the many energy states a single electron can occupy when excited

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?

they are equal

Sketch (a) shows a radiation curve of an incandescent solid and its spectral pattern as produced with a spectroscope. Sketch (b) shows the "radiation curve" of an excited gas and its emission spectral pattern. Sketch (c) shows the curve produced when a cool gas is between an incandescent source and the viewer; the corresponding spectral pattern is left as an exercise for you to construct. Sketch (d) shows the spectral pat-tern of an incandescent source as seen through a piece of green glass; you are to sketch in the corresponding radiation curve.

this answer is a sketch

What is a spectroscope, and what does it accomplish?

A spectroscope is a device that measures the frequencies of light in a beam of light.

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 lines against a bright rainbow background.

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. Because atoms in a solid are closely packed, radiation from them (and liquids) is smeared into a broad distribution to produce a continuous spectrum, whereas radiation from widely spaced atoms in a gas is in separate bunches that produce discrete "lines" when diffracted by a grating.

Which has the higher frequency: red or blue light? Which has the greater energy per photon: red or blue light?

Blue has a higher frequency and greater energy per photon

When a gas glows, discrete colors are emitted. When a solid glows, the colors are smudged. Why?

In a gas, the electrons don't interact with other atoms. In a solid, electrons jump from atom to atom

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.