Variable Symbols
Variable Units
∆E
Radioactive Decay
Name That Force
100
f
frequency
100
E
joules or J
100
In the figure, the amount of energy absorbed when an electron goes from the n=1 to n=3 level
12.08 eV
100
mass number of a beta particle
0
100
In beta decay, this force converts a neutron to a proton
weak nuclear force
200
lambda
wavelength
200
K
joules or J
200
The energy of a photon with a frequency of 2 x 1015 Hz.
1.3x10-18 J
200
atomic number of an alpha particle
2
200
This force is always attractive and partially explains why electrons are attracted to protons.
gravitational force
300
h
Planck's constant
300
c
m/s
300
The energy of a green photon (440 nm)
4.5 x 10-19 J
300
What element is X and what is the mass number?
Thorium-231
300
What two forces could exist between an electron and a proton?
gravitational and electrostatic
400
c
speed of light
400
lambda
m
400
On the picture, which transition emits light with the longest wavelength?
B
400
In radioactive decay, a particle is emitted from the nucleus of an atom, and the atom's atomic number increases by one. What is the emitted particle?
an electron
400
What three forces could exist between a proton and a proton?
gravitational, electrostatic and strong nuclear
500
Phi
work function
500
m
kg or kilogram
500
A certain metal is illuminated with light of a frequency of 1.7x1015 Hz. Electrons are ejected with a speed of 8.4x105 m/s. What is the work function of the metal?
8.03x10-19 J
500
In the radioactive decay equation given below, what is X?
gamma ray (or photon)
500
The primary reason that very large nuclei are unstable is due to
repulsive force of the protons