# Chapter 4: Bohr's Model of the Atom¶

## Example 4.1, Page 86¶

In [1]:
import math

#Variable declaration
rho=9*10**9#in nt-m2/coul2
e=1.6*10**-19#coul
r=1*10**-10#in m

#Calculations
k=(rho*e**2)/(r**3)#nt/m
m=9.11*10**-31#in kg
c=3*10**8#in m/s
v=(1/(2*math.pi))*math.sqrt(k/m)
lamda=c/v

#Result
print "Part(b)\nThe wavelength is %.1e m "%lamda

Part(b)
The wavelength is 1.2e-07 m


## Example 4.2, Page 89¶

In [2]:
import math

#Variable declaration
N=10**4#in rad, Number of atoms tarversed

#Calculations
theta=(2*10**-2)/math.sqrt(N)

#Result
print "Average deflection %.1e rad "%theta

Average deflection 2.0e-04 rad


## Example 4.6, Page 102¶

In [3]:
#Variable declaration
rho=9*10**9#in nt-m2/coul2
m=9.11*10**-31#in kg
e=1.6*10**-19#coul
h=1.05*10**-34#in j-sec

#Calculations
E=-(rho*m*e**4)/(2*h**2)

#Result
print "Binding energy is %.2e Joule "%E
#Answer given in the book is wrong

Binding energy is -2.44e-28 Joule


## Example 4.9, Page 106¶

In [4]:
#Variable declaration
mu=207#207*me

#Calculations&Results
M=1836#183*me
u=(mu*M)/(mu+M)
D=(1./u)*5.3*10**-11
print "Part(a)\nMuon nucleus seperation is %.1e m "%D

E=-u*13.6
print "\nPart(b)\n Binding energy is %.f ev "%E

R=109737#in cm
lamda=(1./u)*(1/0.75)*(1./R)
print "\nPart(c)\n Wavelength is %.1e cm "%lamda

Part(a)
Muon nucleus seperation is 2.8e-13 m

Part(b)
Binding energy is -2530 ev

Part(c)
Wavelength is 6.5e-08 cm


## Example 4.10, Page 107¶

In [5]:
#Calculations&Results

#For Hydrogen atom
R_o=109737#in cm
m=1
M=1836.
RH=(R_o)/(1+(m/M))
print "Spectrum line for Hydrogen occur at %.f /cm "%RH

#For Deuterium atom
R_o=109737#in cm
m=1
M=2*1836.
RD=(R_o)/(1+(m/M))
print "Spectrum line for Deuterium occur at %.f /cm "%RD

Spectrum line for Hydrogen occur at 109677 /cm
Spectrum line for Deuterium occur at 109707 /cm