Theory of Light

Question 1

the electromagnetic radiation of any wavelength

Answer 1

Light

Question 2

value of the speed of light

Answer 2

3.00x10^8 m/s

Question 3

True or False: light travels faster through matter

Answer 3

False: light travels slower through matter

Question 4

4 primary properties of light

Answer 4

1. intensity
2. propagation direction
3. frequency/wavelength
4. polarization

Question 5

the branch of physics that deals with light

Answer 5

Optics

Question 6

what theory states that light is composed of subatomic particles (quanta) called photons

Answer 6

Particle Theory

Question 7

what theory states that light is a form of radiant energy that travels wave-like from one point to another

Answer 7

Wave Theory

Question 8

this is an experiment that proved that light behaves as a wave and as a particle

Answer 8

Double-slit experiment

Question 9

this is a subatomic particle known to be discrete pockets of energy and carry momentum. It has no mass and travels at the speed of light

Answer 9

Photons

Question 10

The main source of natural light on earth

Answer 10

Sun

Question 11

True or False: the cornea absorbs below 360nm

Answer 11

True

Question 12

contains both electric and magnetic fields that oscillate

Answer 12

electromagnetic radiation

Question 13

• perpendicular to magnetic field
• useful in optical mineralogy
• E

Answer 13

Electric field Vector

Question 14

• perpendicular to the electric field
• small and can be ignored
• B

Answer 14

Magnetic Field

Question 15

True or False: the electric field and magnetic field are perpendicular to the propagation direction of the wave

Answer 15

True

Question 16

• the number of crests/ troughs that pass a given point within a second
• Hertz (Hz) ; F

Answer 16

Frequency

Question 17

distance between two crests

Answer 17

Wavelength

Question 18

amount of kinetic energy

Answer 18

Energy

Question 19

important in understanding how light moves through samples and microscopes

Answer 19

Propagation Direction

Question 20

• represents the direction of propagation of light energy
• not always parallel to wave normal

Answer 20

Light ray

Question 21

what is the relationship of frequency and wavelength?

Answer 21

indirectly proportional

Question 22

• light rays are parallel to wave normal
• same velocity of light in all directions
• bonds are the same in all directions

Answer 22

Isotropic materials

Question 23

examples of isotropic materials

Answer 23

isometric minerals and mineraloids

Question 24

• light rays are not parallel to wave normal
• different velocity of light in all directions
• bonds are not the same in all directions

Answer 24

Anisotropic materials

Question 25

examples of anisotropic materials

Answer 25

- tetragonal - hexagonal - orthorhombic - monoclinic - triclinic

Question 26

True or False: light rays travelling along the same path in the same direction will NOT interfere w/ each other

Answer 26

False: they will interfere with each other

Question 27

distance that one wave lags behind the other

Answer 27

Retardation

Question 28

an interference where two waves are said to be in-phase or in-sync

Answer 28

Constructive Interference

Question 29

an interference where two waves are said to be out of phase or out of sync

Answer 29

Destructive Interference

Question 30

visible light with one wavelength

Answer 30

Monochromatic light

Question 31

visible light with several wavelengths perceived as one color

Answer 31

Polychromatic light

Question 32

amount of light that can successfully PASS THROUGH a medium

Answer 32

Transmission

Question 33

amount of LIGHT ENERGY that materials can absorb, reflect, and scatter

Answer 33

Transmittance

Question 34

incident light hits an object and bounces off

Answer 34

Reflection

Question 35

incident light causes atoms and molecules to vibrate

Answer 35

Absorption

Question 36

bending and spreading of waves around an obstacle

Answer 36

Diffraction

Question 37

light bounces off an object in a variety of directions

Answer 37

Scattering

Question 38

light waves change direction as they pass from one medium to another

Answer 38

Refraction

Question 39

limiting the direction of oscillation

Answer 39

Polarization

Question 40

measures how effective a material is in bending light

Answer 40

Index of refraction

Question 41

most minerals have indices of refraction that fall in the range of ____________.

Answer 41

1.4 to 2.0

Question 42

this law states that light is refracted towards the normal upon a medium with higher index of refraction

Answer 42

Snell's Law

Question 43

ordinary light that vibrates in all directions

Answer 43

Unpolarized

Question 44

True or False: All crystalline materials are birefringent

Answer 44

False: not all, isotropic materials are not birefringent

Question 45

the difference of the indices of refraction that associated with different crystallographic directions

Answer 45

Birefringence

Question 46

True or False: materials with high index of refraction accelerates the velocity of transmitted light

Answer 46

False: materials with high index of refraction slows the velocity of transmitted light

Question 47

this visible light has the highest frequency

Answer 47

Violet

Question 48

this visible light has the lowest frequency

Answer 48

Red