# Chapter1-Fundamental Concepts¶

## Ex1-pg21¶

In :
##Chapter 1, Example 1.1, Page 21
import math
##Find Atomic weight of Boron
I10 = 0.199 ## Isotopic abundance of B10 (Value used in question is wrong)
A10 = 10.012937 ##Atomic weight of B10
I11 = 0.801 ## Isotopic abundance of B11
A11 = 11.009306 ##Atomic weight of B11
##Calculation
W = (I10*A10)+(I11*A11)
print'%s %.2f %s'%("The atomic weight of Boron = ",W,"");

##Answers may vary due to round off error

The atomic weight of Boron =  10.81


## Ex2-pg22¶

In :
##Chapter 1, Example 1.2, Page 22
import math
##Find number of 10B molecules in 5g of Boron
m = 5. ##g
Na = 0.6022*10**24 ##atoms/mol
AB = 10.811 ##Atomic weight of 10B , g/mol
NB = (m*Na)/(AB)
print'%s %.2e %s'%("The number of Boron atoms = ",NB," atoms");

##Answers may vary due to round off error

The number of Boron atoms =  2.79e+23  atoms


## Ex3-pg22¶

In :
##Chapter 1, Example 1.3, Page 22
import math
##Estimate the mass on an atom of U 238. From Eq. (1.3)
##Calculating the approximate weight
Mapprox = 238./(6.022*10**23)
##Calculating the precise weight
M = 238.050782/(6.022142*10**23)
print'%s %.2e %s'%("The approximate mass on an atom of U 238 = ",Mapprox," g/atom");
print'%s %.2e %s'%("\n The precise mass on an atom of U 238 = ",M," g/atom")
print("Varies by a negligible error")
##Answers may vary due to round off error


The approximate mass on an atom of U 238 =  3.95e-22  g/atom

The precise mass on an atom of U 238 =  3.95e-22  g/atom
Varies by a negligible error


## Ex4-pg23¶

In :
##Chapter 1, Example 1.4, Page 23
import math
##Density of Hydrogen atom in water
p = 1. ## density of water in g cm^-3
Na = 6.022*10**23 ## molucules/mol
A = 18. ## atomic weight of water in g/mol
N = (p*Na)/A
NH = 2.*N
print'%s %.2e %s'%("The density of water = ",N," molecules/cm3");
print'%s %.2e %s'%("\n The density of hydrogen atoms = ",NH," atoms/cm3");
##Answers may vary due to round off error

The density of water =  3.35e+22  molecules/cm3

The density of hydrogen atoms =  6.69e+22  atoms/cm3