Size of atoms
Dot size corresponds to atom size.

For gases, the density at boiling point is used.   Size data


Copper atoms stack like cannonballs. We can calculate the atom size by assuming the atoms are shaped like either cubes or spheres. For copper atoms,

Density         = D              = 8900 kg/m3
Atomic mass unit= M0             =  1.6605⋅10-27 kg
Atomic mass     = MA             =  55.845 Atomic mass units
Mass            = M   =  MA⋅M0   = 9.785⋅10-26 kg
Number density  = N   =  D / M   = 9.096e28 atoms/m3
Cube volume     = Υcube= 1 / N    = 1.099⋅10-29 m3          Volume/atom if the atoms are cubes
Cube length     = L   =  Υ1/3cube = 2.22⋅10-10 m            Side length of the cube
Sphere fraction = f   =  π/(3√2) = .7405                 Fraction of volume occupied by spheres in a stack o spheres
Sphere volume   = Υsph =  Υcube f = 8.138⋅10-30 m3 = 43πR3  Volume/atom if the atoms are spheres
Sphere radius   = R              = 1.25⋅10-10 m

Strength and density
Dot size  =  Density
Color     =  Shear Modulus, an indicator of the element's strength.

Blue:    The element is a liquid at room temperature
Red:     Weak
White:   Strong
Shear data Density data
Solar abundance

Dot size  =  log(Solar Abundance)
Elements with a dot size of zero have no stable isotope.

Solar abundance data


Color     =   Price per kilogram
Dot size  =  -log(Solar Abundance)      The smaller the dot, the more abundant the element.

Red:   Cheap
White: Expensive
Price data

Bohr model of the atom

The "de Broglie wavelength" of a particle is

Particle momentum    =  Q
Planck constant      =  h  =  6.62*10^-34 Joule seconds
Particle wavelength  =  W  =  h/Q             (de Broglie formula)
The Bohr hypothesis states that for an electron orbiting a proton, the number of electron wavelengths is an integer. This sets the characteristic size of a hydrogen atom.
Orbit circumference  =  C  =  N W           where N is a positive integer

  N   Orbital

  1     S
  2     P
  3     D
  4     F

Electron mass      =  m                =  9.11*10-31 kg
Electron velocity  =  V
Electron momentum  =  Q  = m V
Electron charge    =  e                =  -1.60*10-19 Coulombs
Coulomb constant   =  K                =  9.0*109  Newtons meters / Coulombs2
Electric force     =  Fe  =  K e2 / R2
Centripetal force  =  Fc  =  M V2 / R
Orbit radius       =  R  =  N h2 / (4 π2 K e2 m)  =  N * 5.29e-11 meters
Electron energy    =  E  =  - .5 K e2 / (R N2)    =  N-2 2.18e-18 Joules  =  N-2 13.6 electron Volts          (Ionization energy)
For an electron on a circular orbit,
Fe = Fc




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