Chapter 29 : Nuclear Physics

Example 1 Page No: 916

In [2]:
from __future__ import division
from math import pi
m=1.67*10**-27 #mass of nucleus in kg
ro=1.2*10**-15 #in meter
p=(3*m)/(4*pi*(ro)**3)
print "Nuclear density = %0.2e kg/m3"%p

Nuclear density = 2.31e+17 kg/m3

Example 2 Page No: 920

In [3]:
mp=1.007825 #in u
mn=1.008665 #in u
md=2.014102 #in u
u=931.494 #Mev
M=mp+mn
delta_m=(M-md) #in u
E=delta_m*u
print "Binding energy of Deuteron = %0.2f Mev"%E

Binding energy of Deuteron = 2.22 Mev

Example 3 Page No: 922

In [5]:
No=3*10**16 #no.of radioactive nuclei present at t=0
t_half=1.6*10**3 #years
T_half=t_half*3.16*10**7 #in sec
d=0.693/T_half
R_o=d*No # decays/s
Ci=3.7*10**10
Ro=R_o/Ci
print "Activity or decay rate at t=0 = %0.2e Ci"%Ro

Activity or decay rate at t=0 = 1.11e-05 Ci

Example 4 Page No: 923

In [2]:
from math import exp
T_half=3.83 #half life time of Radon in days
No=4*10**8 #Initial No .of Radon atoms 
lamda=0.693/T_half # in days
t=12 
N=No*exp(-(lamda*t))
print "a) No.of atoms remaining after 12 days : %0.f"%N
lamda_=lamda/(8.64*10**4)
R=lamda_*No
print "Initial activity of the radon sample = %0.2f decay/sec"%R

a) No.of atoms remaining after 12 days : 45612654
Initial activity of the radon sample = 837.68 decay/sec

Example 5 Page No: 925

In [8]:
m_d=222.017571 #mass of daughter nuclei in atomic units
m_alpha=4.002602 #mass of alpha particle in atomic units
M_p=226.025402 #mass of parent nuclei in atomic units
m=m_d+m_alpha
delta_m=(M_p-m)
E=delta_m*931.494
print "Energy liberated = %0.2f Mev"%E

Energy liberated = 4.87 Mev

Example 6 Page No: 927

In [10]:
M_C=14.003242 #mass of carbon in atomic mass units
M_N=14.003074 #mass of nitogen in atomic mass units
delta_M=M_C-M_N
E=delta_M*(931.494)
print "Energy released in beta decay = %0.3f Mev"%E

Energy released in beta decay = 0.156 Mev

Example 7 Page No: 928

In [12]:
from math import log
T_half=3.01*10**9 #half life time in min
lamda=0.693/T_half
R=200 # in decay/min
R0_=15 #decay rate in decay/min.g
m=50 #weight of carbon
R0=R0_*m #in decay/min
t1=-(log(R/R0)/lamda) #im min
t=t1/525949
print "Age of the skeleton = %0.2f years"%t

Age of the skeleton = 10915.43 years