Lecture 14 - Light

Question 1

wavelength is usually in…

Answer 1

cm or nm

Question 2

definition of frequency (v)

Answer 2

the number of wavelengths that pass a particular point per second

Question 3

what is frequency measured in?

Answer 3

cycles per second or s^-1 in Hertz

Question 4

what is electromagnetic radiation?

Answer 4

(light) has an electrical field/wave and a magnetic field perpendicular with the same wavelength and frequency

Question 5

how does light travel?

Answer 5

at 3.00 x 10^8 m/s

Question 6

what is the top row of numbers on the electromagnetic spectrum?

Answer 6

wavelength (nm)(goes from left to right)

Question 7

what is the bottom row of numbers on the electromagnetic spectrum?

Answer 7

frequency (s^-1)(goes from right to left)

Question 8

what is E = hv?

Answer 8

(h is a constant) if v increases, the photon’s (“packets” of light energy) energy increases

Question 9

what does the acronym Roy G. Biv list?

Answer 9

colors of the rainbow; lining up with increasing frequency (red lowest, violet highest)

Question 10

to find wavelength when given frequency…

Answer 10

λ = c/v

Question 11

to find frequency when given wavelength & speed…

Answer 11

v = c/λ

Question 12

to find the energy of a photon when given frequency…

Answer 12

E = hv

Question 13

to find the energy of a photon when given wavelength…

Answer 13

E = (hc)/λ

Question 14

what symbol represents wavelength?

Answer 14

λ

Question 15

what symbol represents frequency?

Answer 15

v

Question 16

what symbol represents speed (of light)?

Answer 16

c

Question 17

what symbol represents energy?

Answer 17

E

Question 18

what symbol represents Planck’s constant?

Answer 18

h

Question 19

what is Planck’s constant?

Answer 19

6.626 x 10^-34 Js