# Chapter 2: Introduction to Quantum Mechanics¶

## Example 2.1, Page 47¶

In [2]:
#Variable declaration
lamda=0.708*10**-8# cm
h=6.625*10**-34# J*s Plank's constant
c=3.0*10**10# cm/s
e=1.6*10**-19# eV

#Calculations&Results
E=(h*c)/lamda# E=hv=hc/lamda
print "The value of E is %.2e J"%E
E=E/e
print "The value of E is %.2e eV"%E

The value of E is 2.81e-15 J
The value of E is 1.75e+04 eV


## Example 2.2,Page 49¶

In [3]:
#Variable declaration
m=9.11*10**-31# kg*m/s
v=10**5#m/s
h=6.625*10**-34#js

#Calculations&Results
p=m*v
print "momentum is %.2e"%p
lamda=h/p
print "de broglie wavelength in meter is %.2e"%(lamda)

momentum is 9.11e-26
de broglie wavelength in meter is 7.27e-09


## Example 2.3, Page 58¶

In [4]:
import math

#Variable declaration
a=5*10**-10# a=5A = 5*10**-8cm
h=1.054*10**-34# J*s Planck's constant
m=9.11*10**-31# kg*m/s
e=1.6*10**-19# eV

#Calculations&Results
print "The energy levels are:"
for n in range(1,4):
En=((h**2*n**2*math.pi**2)/(2*m*a**2))/e
print "For n = %d, E = %.2f eV"%(n,En)


The energy levels are:
For n = 1, E = 1.50 eV
For n = 2, E = 6.02 eV
For n = 3, E = 13.54 eV

In [ ]: