Complete the following table.

 

Atomic Number

Mass Number

Number of Neutrons

Number of Protons

Number of Electrons 

Name of the Atomic Species

9

-

10

-

-

-

16

32

-

-

-

Sulphur

-

24

-

12

-

-

-

2

-

1

-

-

-

1

0

1

0

-

 

 

Answer

 

Following are the formulae used while computing the table:

 

  1. Atomic number = Number of protons = Number of electrons
  2. Mass number = Number of protons + Number of neutrons
  3. Number of neutrons = Mass number - Number of protons/electrons

                                       = Mass number - Atomic number

  • First row:
    i) Atomic number = 9 ,
    Therefore, the number of protons = number of electrons = 9 
    ii) Mass number = Number of protons + Number of neutrons = 9 + 10 = 19.
    (iii) The atomic species having atomic number 9 is Fluorine.

 

  • Second row:
    i) Atomic number = 16 ,
    Therefore, the number of protons = number of electrons = 16 
    ii) Mass number - Number of protons = Number of neutrons
    = 32 - 16 = 16

 

  • Third row:
    i) Number of protons = 12
    Therefore, Number of protons = Number of electrons = Atomic number = 12
    so the atomic number is 12 and the number of electrons is also 12.
    ii) Mass number - Number of protons = Number of neutrons
    = 24 - 12 = 12.
    iii) The atomic species of atomic number 12 is Magnesium.

 

  • Fourth row:
    i) Number of protons = 1 ,
    So, Number of protons = Number of electrons = Atomic number = 1
    ii) Mass number - Number of protons = Number of neutrons
    = 2 -1 = 1.

    iii) The atomic species of atomic number 1 and mass number 2 is heavy Hydrogen or Deuterium.

 

  • Fifth row:
    i) Number of protons = 1 ,
    So, Number of protons = Atomic number = 1

    ii) The atomic species of atomic number 1 and mass number 1 is ordinary Hydrogen.
    But since Number of electrons = 0, it is Hydrogen ion H+.



Now, we can complete the table using the above calculations: -

 

Atomic Number

(Z=p and e)

Mass Number

(A = p+n)

Number of Neutrons

(n)

Number of Protons

(p)

Number of Electrons 

(e)

Name of the Atomic Species

9

9+10 = 19

10

9

9

Fluorine

16

32

32-16= 16

16

16

Sulphur

12

24

24-12= 12

12

12

Magnesium

1

2

2-1= 1

1

1

Deuterium

1

1

0

1

0

Hydrogen ion

  1. Class 9
  2. Chapter 4 Class 9 - Structure of Atom (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo