Calculate the number of neutrons, protons and electrons
  
(i) atomic number \(3\) and mass number \(7\).
  
(ii) atomic number \(92\) and mass number \(238\).
 
(I) Atomic number \(=\) \(3\)
 
Mass number \(=\) \(7\)

So, number of electrons (or) number of protons \(=\) 

Mass number \(=\) Number of protons \(+\) Number of neutrons
 
So, number of neutrons \(=\) 
 
(ii) Atomic number \(=\) \(92\)
 
Mass number \(=\) \(238\)

So, number of electrons (or) number of protons \(=\) 

Mass number \(=\) Number of protons \(+\) Number of neutrons
 
So, number of neutrons \(=\)