##Chapter 3, Example 3.1, Page 66
import math
##Energy required to remove electron in the ground state
##Obtaining values from table 1.5
h = 6.626*10**-34 ## J s
m = 9.109*10**-31 ## kg
e = 1.6022*10**-19 ## C
E0 = 8.854*10**-12 ## F m^-1
E1 = -(m*(2.*e**2)**2)/(8.*E0**2*h**2)
EJ = E1/(1.6022*10**-19) ## converting to eV
print'%s %.2e %s'%("\n E1 in Joules = ",E1," J");
print'%s %.2f %s'%("\n E1 in eV = ",EJ," EV");
##Answer may vary due to round off error
##Chapter 3, Example 3.2, Page 79
import math
## Estimate the mass of Ga
##Based on equation 3.16
av = 15.835 ## MeV
As = 18.33 ## MeV
ac = 0.714 ## MeV
aa = 23.30 ## MeV
ap = 11.2 ## MeV
A = 70.
c2 = (1./931.5)
mn = 1.0072765
mp = 1.0086649
me = 0.00054858
a = av*A
b = As*A**(2/3.)
c = ac*(31**2/A**(1./3.))
d = aa*((A-62.)**2/A)
c = ap/math.sqrt(A)
BE = (a-b-c-d)*c2 ## BE/C^2
M = 31.*mn+39.*mp-BE+31.*me
print'%s %.2f %s'%("\n Nuclear binding energy = ",BE," u"); ## answer provided in the textbook is wrong
print'%s %.2f %s'%("\n Atomic mass = ",M," u");
##Answer may vary due to round off error