Exam 3: Light and Matter: the Inner Workings of the Cosmos

When an electron in a hydrogen atom drops from the second to the first excited energy state it emits a bright red emission line called hydrogen alpha.

Give at least two advantages of the Kelvin temperature scale for astronomers.

A wave's velocity is the product of the

In the Doppler effect, a redshift of spectral lines shows us the source is receding from us.

The greater the disturbance of the medium, the higher the amplitude of the wave.

Observations in the X- ray portion of the spectrum are routinely done from the surface of the Earth.

In general, the spectral lines of molecules are

In the Kelvin scale, absolute zero lies at

What information about a star can be inferred from its Doppler shift?

How does Stefan's law and a knowledge of Earth's history tell us that the Sun's temperature cannot have varied much in the last 3.5 billion years?

How can Wein's law be used to determine the temperature of a star?

In the Bohr model of the atom, an electron can only exist in specific, well- defined energy levels.

The observed spectral lines of a star are all shifted towards the red end of the spectrum. Which statement is true?

What is true of a blackbody?

Explain the appearance of the Sun's spectrum, as noted by Fraunhofer.

The Zeeman effect reveals the presence of strong magnetic fields by the splitting of spectral lines.

When an electron moves from a lower to a higher energy state, a photon is .

Explain how the Zeeman effect allows us to study stellar magnetic fields.

According to Wein's law, the wavelength of the peak energy will be if the temperature of the blackbody is doubled.

A dense, hot body will give off a(n) spectrum.