Modern Physics - Formula - Level 3 Flashcards
(45 cards)
Energy
Symbol - E
Units - Joules (J)
Planck’s constant (6.63 x 10^-34)
Symbol - h
Units - Joule seconds (Js)
Frequency
Symbol - f
Units - Hertz (Hz)
or Seconds inverse (s^-1)
Work function
Symbol - Φ
Units - Joules (J)
Kinetic energy of an electron
Symbol - Ek
Units - Joules (J)
Charge of an electron (1.6 x 10^-19)
Symbol - e
Units - Coulomb (C)
Velocity of electron
Symbol - v
Units - Metres per second (ms^-1)
Mass
Symbol - m
Units - Kilograms (kg)
Rydberg constant
Symbol - R
Units - Meters inverse (m^-1)
Wavelength
Symbol - λ
Units - Meters (m)
Speed of light (velocity of radiation) (3 x 10^8)
Symbol - C
Units - Meters per second (ms^-1)
Energy value for a given energy level (n)
Symbol - En
Energy level number (1, 2, 3 ,…)
Symbol - n
Final energy level (first in equation)
Symbol - S
Inital energy level (second in equation)
Symbol - L
Equation for energy of a photon (from frequency)
Epho = hf
Where,
f is the frequency of the incident light
Equation for energy of a photon, when given the wavelength
Epho = hC/λ
Where,
λ is the wavelength of the radiation
What is the velocity of radiation equal to?
C = λf
Equation for photoelectric effect
Epho = Φ + Ek max
Where,
Epho is the energy present in the incident photon
Φ is the work function of the metal surface
Ek max is the maximum kinetic energy of the ejected photoelectron
Equation for threshold frequency
hfo = Φ
Where,
fo is the threshold frequency
Φ is the work function of the metal
Equation for kinetic energy and electrical potential energy
hf = hfo + 1/2 me ve^2
Where,
hf is the energy present in the incident photon
hfo is threshold frequency
1/2 me ve^2 is the kinetic energy of the electron
hf = hfo + Ve
Where,
hf is the energy present in the incident photon
hfo is threshold frequency (work function)
Ve is the electrical potential energy
(hfo + Ve = hfo + 1/2 me ve^2)
Converting from nano and micrometers to meters
Nano x 10^-9
(Mew) Micro x 10^-6
Converting from volts or joules to electronvolts
(Volts or joules) / (1.6 x 10^-19)
Converting from Megahertz to hertz
Megahertz x 10^6