_______________physics 1.Matter is a____________________ 2.Light is a _________________. particle wave Classical This is "everyday" physics that deals.

Presentation on theme: "_______________physics 1.Matter is a____________________ 2.Light is a _________________. particle wave Classical This is "everyday" physics that deals."— Presentation transcript:

_______________physics 1.Matter is a____________________ 2.Light is a _________________. particle wave Classical This is "everyday" physics that deals with objects that are relatively 1. _____________  bigger than _____________ 2. _____________  v << _____ largeatoms slow _______________ modified classical physics so that it would give more accurate results when speeds _______________________________ and for________________. His theories are called the ________________ and ________________ Theories of _________________________. c Einstein were close to c Special General Relativity gravity

_______________ physics modified physics to deal with _________________________ on the scale of ___________. According to this theory: 1. Matter can act like a___________________________. 2. Light can act like a___________________________. Ex: Light in the classical view acts like a ___________ whose _________________ determines its energy:  _______________  more____________ Modern tiny objects atoms particle or a wave wave energy brighter amplitude

Ex: The ___________________ effect showed that light can act like a ______________________. shine light zinc electrons e - “photo…”“…electric” color of light brightness of light how many electrons were ejected from the zinc and with what KE reddimno e - redbrightno e - violetdima few e - with lots of KE violetbrightlots of e- with lots of KE photoelectric particle

wave particle Duality:

Einstein _____________________________ for a paper that explained the photoelectric effect by assuming light acted like ______________. The higher its _______________ the greater the energy of the light particle. Bright light consists of ___________ particles. _______________ light: ________________light: dim violet bright violet none of these many _______ energy particles could eject an e - bright red dim red won a Nobel Prize ________________light: particle low frequency  1_______ energy particle cannot eject an e - each of these many ________ energy particles could eject an e -  1_______ energy particle can eject 1 e - low high many

E ph = where h = = E ph f The ______________ (basic unit) of electromagnetic energy (light) is called a _______________. It has no mass, but carries ______________ and ________________. Its energy is given by: quantum photon energymomentum Ex: What is the relationship between Eph and f? What quantity does the slope of the line?

See page 1 of Reference Tables

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E ph = where h = = E ph f The ______________ (basic unit) of electromagnetic energy (light) is called a _______________. It has no mass, but carries ______________ and ________________. Its energy is given by: quantum photon energymomentum Ex: What is the relationship between E ph and f? What quantity does the slope of the line? hf Planck's constant 6.63 x 10 -34 J·s h Eph/f = ?

E ph Start with the equation: Substitute c in for v: Solve for f: Substitute in the equation for Ex: What is the relationship between E ph and ? v = f c = f f = c/ E ph = hf E ph = hc/ Ex: What is the relationship between E ph and in graph form? The greater the wavelength, the ___________ the energy.

E ph Start with the equation: Substitute c in for v: Solve for f: Substitute in the equation for Ex: What is the relationship between E ph and ? v = f c = f f = c/ E ph = hf E ph = hc/ Ex: What is the relationship between E ph and in graph form? The greater the wavelength, the ___________ the energy. less

Ex: Find the energy of a blue light photon in joules. E ph = hf = hc  = (6.63 x 10 -34 J·s) (???) Convert the answer to electronvolts (eV). page 1 of RT: 1 eV = ________________ J

Choose f = 6.5 x 10 14 Hz

= (6.63 x 10 -34 J·s) = 4.3 x 10 -19 J page 1 of RT: 1 eV = ________________ J Ex: Find the energy of a blue light photon in joules. E ph = hf = hc/ Convert the answer to electronvolts (eV). (6.5 x 10 14 Hz)

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= (6.63 x 10 -34 J·s) = 4.3 x 10 -19 J See page 1 of RT: 1 eV = ________________ J 1.6 x 10 -19 E ph = 4.3 x 10 -19 J x Ex: Find the energy of a blue light photon in joules. Convert the answer to electronvolts (eV). _______1 eV_______ 1.6 x 10 -19 J (6.5 x 10 14 Hz) E ph = 2.7 eV E ph = hf = hc/

_____________ theory - ____________________ energy is emitted from and absorbed by _______________ in _____________ amounts or ________________. ( ______________ means "separate, individual pieces.") Quantum electromagnetic matter discrete "packets" Discrete atom Ex: _______________ of a photon Ex: _____________ of a photon before: after: atom has ______ energy atom before: after: atom has _______ energy more less absorption emission

Ex The ____________Effect: X-rays scatter off electrons. e- at rest  KE =____ v=c _______ photon before collision: after collision: e- ____________ c The scattered photon now has _______ energy. So its f is _______ and its  is ______________ Both _________________and ______________ are conserved. Compton 0 now has KE momentum energy x-ray less longer

In sum, light can act like a __________________ or like a ____________. Which one it acts like depends on the situation. When light interacts with.. Even when it is described as a photon, we still use __________ properties such as _______________ and _________________ to describe it. … __________, it acts like a _________________ Examples: 1/ __________________ 2/ __________________ particle wave light wave interference diffraction … ___________, it acts like a __________________ Examples: 1/ __________________ 2/ __________________ 3/ __________________ atoms particle absorption emission collisions wave frequency wavelength

F e =___ F g =_____ oil drop By suspending the oil drop then letting it fall, he was able to discover that the oil drops always carried an ___________________________ of the fundamental charge = ______________________ (the ______________ of charge). which is the charge on 1 _____________ or _____________.  Charge is __________________. integer multiple 1.6 x 10 -19 C mg quantized quantum proton electron oil electric qE Electron charge: In 1909, Millikan sprayed drops of ________ into an _______________ field E.

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