Term
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Definition
| consists of a nucleus surrounded by a cloud of electrons |
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Term
| what does the nucleus consist of? |
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Definition
| positively-charged protons and uncharged neutrons |
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Term
| What does the number of protons in an atom determine? |
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Definition
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Term
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Definition
| atoms of the same element (same # of protons) but have different number of neutrons |
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Term
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Definition
| an atom that has lost or gained an electron |
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Term
| A neutron is surrounded by a number of negatively charged electrons equal to what? |
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Definition
| the number of protons in the nucleus |
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Term
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Definition
| two or more atoms joined together |
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Term
| how are the electrons in an atom attracted to the nucleus? |
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Definition
| The Coulomb force (binding energy that holds electrons in at atom) |
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Term
| What does the size of an electron's orbit depend on? |
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Definition
| it's energy (orbits can be thought of as energy levels) |
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Term
| Why are an electrons orbits thought of as energy levels? |
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Definition
| because the size of an electrons orbit depends on the energy |
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Term
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Definition
| an electron is excited to a higher orbit by a collision between atoms or absorption of a photon. |
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Term
| What is the lowest possible orbit known as? |
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Definition
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Term
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Definition
| the agitation among the atoms and molecules of an object |
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Term
| What is the flow of thermal energy? |
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Definition
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Term
| what does temperature refer to? |
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Definition
| the intensity of the thermal energy (the agitation) |
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Term
| What causes the emission of black body radiation? |
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Definition
| the motion among the particles in a body |
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Term
| The hotter an object is, does it radiate more or less? does it have a shorter/longer wavelength of maximum intensity? |
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Definition
| radiates more and has a shorter wavelength |
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Term
| When can an atom emit or absorb a photon? |
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Definition
| when an electron makes a transition between orbits |
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Term
| What types of series does the Hydrogen atom have for each spectrum? |
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Definition
1. Lyman Series of lines in Ultraviolet
2. Balmer Series in the visible
3. Paschen Series in the infrared |
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Term
| What does the strength of spectral lines depend on? |
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Definition
| the temperature of the star |
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Term
| What is the star's spectral class determined by? |
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Definition
| the absorption lines in its spectrum |
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Term
| Why is the spectral sequence important? |
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Definition
| because it is a temperature sequence |
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Term
| What does the astronomer learn by classifying the star? |
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Definition
| the temperature of the stars surface |
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Term
| What can a spectrum tell you about the star? |
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Definition
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Term
| What is the Doppler EffecT? |
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Definition
| the change in the wavelength of radiation due to relative radial motion of source and observer |
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Term
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Definition
| when a star is approaching and you observe slightly shorter wavelengths |
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Term
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Definition
| when a star is receding and you observe longer wavelengths |
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Term
| what does the doppler effect reveal? |
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Definition
| the stars radial velocity |
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Term
| What is doppler broadening of spectral lines caused by? |
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Definition
| motions of the atoms in a hot gas |
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Term
| what is collisional broadaning caused by? |
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Definition
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Term
| What does broadening depend on? |
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Definition
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Term
| List six things that astronomers can study about a star just by receiving its light. |
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Definition
1. total energy output
2. surface temperature
3. radius
4. chemical composition
5. velocity relative to earth
6. rotation period |
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Term
| What are the particles that make up a nucleus? |
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Definition
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Term
| What is the most abundant atom? |
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Definition
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Term
| TRUE OR FALSE: any energy can excite an electron |
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Definition
| false, it has to be exactly the right amount of energy |
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Term
| What does the color of the star tell us about? |
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Definition
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Term
| What is the spectrum of a stars light, or any nearly thermal spectrum, called? |
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Definition
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Term
| the hotter the object is, what does it emit more of? |
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Definition
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Term
| What is the first law of black body radiation? |
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Definition
| the hotter an object, the more energy it emits |
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Term
| According to the Wein's displacement law, as temperature increases, what does the peak wavelength of a blackbody spectrum do? |
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Definition
| shifts toward shorter wavelengths |
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Term
| What is the second law of Black Body Radiation? |
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Definition
| That as the temperature increase, the peak wavelength of a blackbody spectrum shifts to shorter wavelengths |
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Term
| A solid, liquid, or dense gas that is excited to emit light produces what kind of spectrum? |
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Definition
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Term
| A low density gas excited to emit light produces what kind of spectrum? |
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Definition
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Term
| If light comprising a continuous spectrum passes through a cool, low-density gas, what will the result be? |
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Definition
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Term
| If light comprising a continuous spectrum passes through a cool, low-density gas, what will the result be? |
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Definition
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Term
| What are Kirchoff's three laws of radiation? |
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Definition
1. a solid, liquid, or dense gas excited to emit light produces a continuous spectrum
2. a low-density gas excited to emit light produces an emission spectrum
3. if light comprising a continuous spectrum passes through a cool, low-density gas, the result is an absorption spectrum |
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Term
| What kind of spectra are the spectra of starS? |
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Definition
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Term
| What are the most prominent lines in many astronomical objects called? |
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Definition
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Term
| List the Spectral classes from highest temperature to lowest temperature. |
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Definition
O B A F G K M
(Oh Be A Fine Guy, Kiss Me!) |
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Term
| What can relative strengths of absorptions lines tell us about stars? |
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Definition
| the composition of the stars |
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Term
| If a light source is moving towards an observer what kind of shift is there? |
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Definition
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Term
| if a light source is moving away from an observer, what kind of shift is there? |
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Definition
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Term
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Definition
| the component of velocity along your line of sight |
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Term
| Does light excite electrons into higher or lower energy states? |
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Definition
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Term
| the longer the wavelength, the higher or lower the temperature? |
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Definition
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Term
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Definition
| energy given off in form of radiation |
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