1 molecule of  contains electrons = 6 + 4 = 10

                                     

(a)  1 g atom of carbon = 14g
                               = 6.022 x 10²³ atoms
   Each carbon atom 
     


(b) Mass of 1 neutron = 1.675 x 10^-27 kg
    Mass of 2.4088 x 10²¹ neutrons
      = (1.675 x 10^-27kg) x (2.4088 x 10²¹)
      = 4.0347 x 10^-6kg

Mass of one electron =9.10939 x 10^-31 kg

Therefore, Number of electrons that weigh 9.10939 x 10^-31 kg =1


Number of electrons that will weigh1g= (1x10^-3kg)

=0.1098 X10^-3+31

=0.1098 X10²⁸

=1.098 X10²⁷

One mole of electron
                     
Mass of 1 electron = 
Mass of 
                   
Charge on one electron
           
Charge on one mole electrons
             

(i) The element with atomic number 17 is Cl. Its symbol is 
(ii) The element with atomic number 92 is U. Its symbol is 
(iii) The element with atomic number 4 is Be. Its symbol is