Done by: Chua Wei Hern (9) 2O1

p

rinciple of quantum physics holds that matter and

light exhibit the behaviors of both waves and particles,

depending upon the circumstances of the experiment.

O

ne of the most complex and confusing concept in

physics

BRIEF HISTORYA

ristotle was one of the first to publicly hypothesize about the nature of light, proposing

that light is a disturbance in the element air.  

A

t the beginning of the 11th Century, the Arabic scientist Alhazen wrote the first

comprehensive treatise on optics; describing refraction, reflection, and the operation of a

pinhole lens via rays of light traveling from the point of emission to the eye.

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eginning in 1670 and progressing over three decades, Isaac Newton developed and

championed his corpuscular hypothesis, arguing that the perfectly straight lines

of reflection demonstrated light's particle nature; only particles could travel in such

straight lines.

PHOTOELECTRIC EFFECT

T

he photoelectric effect refers to the emission or ejection of electrons from the surface

of generally a metal in response to incident light.

E

nergy contained within the incident light is absorbed by electrons within the metal,

giving the electrons sufficient energy to be emitted from the surface of the metal.

T

he more intense the incident light, the greater the energy with which the electrons

should be ejected from the metal.

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ne of the experiments for wave-particle duality of light

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way to prove light has particle properties.

PHOTONS

A

n elementary particle

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asic unit of light

I

t is massless

H

as no electric charge

SOURCES

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t

t

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:

/

/

en.wikipedia.org/wiki/Photon

h

ttp://en.wikipedia.org/wiki/Wave

%E2%80%93particle_duality#Brief_history_of_wave_and_particle_viewpoi

nts

h

ttp://physics.about.com/od/lightoptics/a/waveparticle.htm

B

ooks