Astronomy - Light (Part 2)

Front 1

True or False. In a hydrogen atom, one electron is orbiting around a proton?

Back 1

False. One electron orbiting around nucleus. Makes a single proton.
Like a satelite & earth

Front 2

What determines the distance between orbiting electron and nucleus?

Back 2

The energy of the orbit - energy levels

Front 3

Why is it said that the electron's energy level are quantizied?

Back 3

Electron only allowed to orbit in specific energy levels. Different than a satellite, which can orbit at any altitude.

Front 4

What are the 3 things that can happen if a hydrogen atom was struck by a photon coming from a light source?

Back 4

1) Photon has so much energy, knocks electron off atom
2) Photon's energy matches energy difference, photon is absorbed
3) Photon doesnt have right amount of energy to match difference in atom's energy

Front 5

What happens when a Photon has so much energy it knocks an electron off its atom? (3)

Back 5

Leaves ionized atom = process of ionization
Atom becomes a ionized particle = ion
Gas in ionized state becomes PLASMA

Front 6

What happens when a photons energy matches the difference in the atom and the photon is absorbed?

Back 6

Atom acquires energy from photon
Electron "jumps" to higher energy state = excitation
Electron want to go back to "ground state"
Remits the photon with energy to "jump down" = dexcitation

Front 7

What is the Ha (H-alpha), or otherwise known as Balmer alpha, emission?

Back 7

It is a dexcitation, a jump, from level 3 to level 2.
It produces a red emission.
Very important in astronomy

Front 8

What is the wavelength measurement of the H-alpha line?

Back 8

656.3 nm

Front 9

What happens when the photon doesn't have the right amount of energy to match difference in atom's energy?

Back 9

Atom & Photon ignore each other
Photon continues on

Front 10

What are spectral lines?

Back 10

Series of bright, narrow lines that are found in the electromagnetic spectrum produced by a container full of excited hydrogen gas

Front 11

What is the Balmer series?

Back 11

What determines if it cascades or jumps to each level.

Front 12

What is a black body?

Back 12

Hot object with high density.
Hot bulb, star, high density gas/solid
Emits radiation at all wavelengths = RAINBOW

Front 13

What forms emission lines? Why?

Back 13

A hot gas with low density.
Atoms get excited then de-excite to form emission lines

Front 14

What forms an absorption spectra?

Back 14

A cool gas with low density.
Atoms get excited then de-excite to re-emit all original photons

Front 15

Why is some light removed from the continuous spectrum?

Back 15

Photons re-emit in ALL directions. Some light is removed, thus the black lines in the absorption spectra.

Front 16

What spectral lines do molecules emit? (3)

Back 16

Electronic (optical/UV)
Vibrational (IR)
Rotational (radio)