Chapter 2 : Review of Atomic concepts, Atomic Models, and Periodic Table

Example 2.1 page no : 21

In [1]:
# Variables
a1 = 1.0078;			#atomic weight of H-1
a2 = 2.0143;			#atomic weight of H-2
p1 = 99.985;			#% of H-1
p2 = .015;  			#% of H-2

# Calculations
a = ((a1*p1)+(a2*p2))/100

# Results
print "Average atomic weight of Hydrogen  =  %.3f"%a

Average atomic weight of Hydrogen  =  1.008

Example 2.2 page no : 24

In [11]:
# Variables
z = 79.;            			#atomic no. of gold
e = 7.68*1.6*10**-13;			#ke in J
e_c = 1.6*10**-19;	    		#charge of electron in C
e_0 = 8.854*10**-12;			#permittivity F/m

#Calculations
d = (2*e_c**2*z)/(4*3.14*e_0*e);			#distance in m

# Results
print "distance (in m)  =  %.2e m"%d

distance (in m)  =  2.96e-14 m

Example 2.3 pageno : 24

In [3]:
import math 

# Variables
n = 44.;			#no. of particles scattered per minute
a = 90.;			#angle in degrees
b = 75.;			#angle in degrees
d = 135.;			#angle in degrees

# Calculations
x = math.sin(math.radians(a/2));
c = n*x**4;
y = math.sin(math.radians(b/2));
n1 = c/y**4;
z = math.sin(math.radians(d/2));
n2 = c/z**4;

# Results
print "Proportionality constant  =  ",c
print "No. of particles scattered at 75 degree (in per minute)  =  %d"%n1
print "No. of particles scattered at 135 degree (in per minute)  =  %d"%n2

Proportionality constant  =   11.0
No. of particles scattered at 75 degree (in per minute)  =  80
No. of particles scattered at 135 degree (in per minute)  =  15

Example 2.4 pageno : 28

In [5]:
import math 

# Variables
n = 1.          			#first orbit
e_0 = 8.85*10**-12;			#permittivity in freee space
h = 6.62*10**-34;			#planck's consmath.tant
m = 9.1*10**-31;			#mass of an electron in kg
e = 1.6*10**-19;			#charge of an electron in C
z = 1.;

# Calculations
r = n**2*e_0*h**2/(3.14*m*e**2*z);			#radius of first orbit in m
r1 = r*10.**10;			                    #radius in Angstorm

# Results
print "Radius of first orbit of electron in Hydrogen atom (in Angstorm)  =  %.2f A"%r1

Radius of first orbit of electron in Hydrogen atom (in Angstorm)  =  0.53 A

Example 2.5 pageno : 28

In [7]:
import math 

# Variables
e_0 = 8.85*10**-12;			#permittivity in freee space in sqC/N/sqm
h = 6.62*10**-34;			#planck's constant in Js
m = 9.1*10**-31;			#mass of an electron in kg
e = 1.6*10**-19;			#charge of an electron in C
z = 1.;	            		#for hydrogen
n = 1.;

# Calculations
e = m*z**2*e**4/(8*e_0**2*h**2*n**2);			#ionisation energy in J
e1 = e/(1.602*10**-19);			                #in eV

# Results
print "Ionisation Energy (in J)  =  %.2e J"%e
print "Ionisation Energy (in eV)  =  %.1f V"%e1

Ionisation Energy (in J)  =  2.17e-18 J
Ionisation Energy (in eV)  =  13.6 V

Example 2.6 page no : 32

In [8]:
# Variables
n = 4.;     			#fourth orbit

# Calculations
a = (0+1)/n;			#for s suborbit
b = (1+1)/n;			#for p suborbit
c = (2+1)/n;			#for d suborbit
d = (3+1)/n;			#for f suborbit

# Results
print "For s suborbit b/a  =  ",a,"a"
print "For p suborbit b/a  =  ",b,"a"
print "For d suborbit b/a  =  ",c,"a"
print "For f suborbit b/a  =  ",d,"a"

For s suborbit b/a  =   0.25 a
For p suborbit b/a  =   0.5 a
For d suborbit b/a  =   0.75 a
For f suborbit b/a  =   1.0 a

Example 2.7 pageno : 33

In [10]:
# Variables
h = 6.62*10**-34;			#planck's constant in Js
p = 10**-27;			#uncertainity in momentum in kg m/s

# Calculations
x = h/(2*3.14*p);			#uncertainity in position in m

# Results
print "Minimum Uncertainity in Position (in m)  =  %.3e"%x

Minimum Uncertainity in Position (in m)  =  1.054e-07