Astronomy and Cosmology Chap 3 Question

Electrons are about 1000x heavier than protons

False (They are lighter)

In a vacuum, photons of higher energy

have higher frequencies and shorter wavelengths than lower-energy photons

In a particular atom, absorbing a photon with a wavelength of 550nm causes an electron to jump from shell n=2 to shell n=4. When that electron falls back down from shell n=4 to shell n=2, the photon it emits has a wavelength of:

550 nm

In a particular atom, absorbing a photon with a wavelength of 550nm causes an electron to jump from shell n=2 to shell n=4. When that electron falls back down it takes a step-wise route, first falling from n=4 to n=3, then falling from n=3 to n=2. In this step-wise process, it lets out two photons, photon 1 for the first step (from 4 to 3) and photon 2 for the next step (from 3 to 2). Which of the following is true:

Both photon 1 and photon 2 have wavelengths longer than 550nm

The surface temperature of the Sun is about 6000 K. The surface temperature of the star Rigel is 11,000 K. The peak wavelength of Rigel's blackbody radiation is: (choose all correct answers)

Shorter than the Sun's peak wavelength

Has more intensity than the Sun's peak wavelength

If a neutral atom loses one or more electrons, the atom is said to be

ionized

If an object emitting a wave (sound, light, etc) is moving away from you, the frequency you detect is

lower than the original emitted frequency.

Put the following particles in their correct locations:

The nucleus of an atom: Proton, Neutron

A shell around the nucleus of an atom: Electron

In a vacuum, photons of lower energy

have lower frequencies and longer wavelengths than higher-energy photons

If an object emitting a wave (sound, light, etc) is moving towards you, the wavelength you detect is

shorter than the original emitted wavelength

In the Bohr model, what happens when an electron moves from a lower shell to a higher shell?

It absorbs energy

When an electron drops from a higher shell to a lower shell, it:

Emits a photon

Which statements about electron shells are correct?

Larger shell numbers correspond to higher electron energy

Electrons can only occupy specific energy levels

Moving to a higher shell requires energy

Moving to a lower shell releases energy

An atom has a neutral charge when:

It has equal numbers of protons and electrons

Nucleus

Proton

Neutron

Electron shell/cloud:

Electron

Which particle has a negative charge?

Electron

Most of the mass of an atom is located:

In the nucleus

When a neutral atom loses one or more electrons, the atom becomes

ionized

What type of spectrum is produced by a very hot, dense object that gives off many different wavelengths?

Continuous spectrum

A hot gas made of only a few elements produces light at specific wavelengths. This is called:

Emission spectrum

An absorption spectrum is produced when:

A continuous spectrum passes through cooler gas and certain wavelengths are absorbed

For the same gas composition, the emission and absorption spectra:

Have the same characteristic pattern/fingerprint

What does Wien's Law tell us?

Hotter objects have shorter peak wavelengths

Compared with a cooler object, a hotter blackbody generally has: Choose all that apply.

A shorter peak wavelength

A peak shifted toward the blue end

More emission toward the bluer wavelengths

The surface temperature of the Sun is about 6000 K, while Rigel's surface temperature is about 11,000 K. Compared with the Sun, Rigel's peak wavelength is:

Shorter

A photon with a wavelength of 550 nm causes an electron to jump from n = 2 to n = 4. When the electron returns directly from n = 4 to n = 2, the emitted photon has a wavelength:

Exactly 550 nm

An electron falls from n = 4 → n = 3 → n = 2 instead of directly from n = 4 → n = 2.

Compared with the original 550 nm photon, the two emitted photons will each have:

Longer wavelengths than 550 nm

If an object emitting a wave is moving away from you, the frequency you detect is:

Lower than the original frequency

If an object emitting light is moving toward you, the wavelength you detect is:

Shorter than the original wavelength

Blueshift

Light is shifted toward shorter wavelengths

Object is moving toward us

Redshift

Light is shifted toward longer wavelengths

Object is moving away from us

If a hydrogen emission line that should normally appear at 656 nm is observed at 700 nm, what does this tell us?

The object is moving away from us

If two objects produce the same hydrogen emission line, but one appears at 700 nm and another at 750 nm, the object whose line appears at 750 nm is:

Moving away from us faster

What can astronomers learn from studying spectra? Choose all that apply.

An object's temperature

An object's chemical composition

Whether an object is moving toward or away from us

Information about exoplanets through periodic Doppler shifts