Question

Question 19 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 −

Class 9 - Science - Structure of the Atom Page 56

Answer 1

Heya,

The question is not quite clear and quite confusing to answer so please refer to the attachment:-

Answer 2

THE COMPLETED TABLE IS GIVEN IN THE FIGURE ATTACHED BELOW.

Explanation:

• The sum of proton and neutron gives the mass number. The atomic number is equal to proton number.
• The number of proton and electron are equal in an atom.
• The number of neutrons can be calculated by subtracting atomic number from atomic mass.

1. Atomic number =9

  Number of electrons = number of protons = atomic number =9

  Number of neutrons + number of protons = 9+10 = 19

  Atomic specie = Fluorine

2. Atomic number =16

  Number of electrons = number of protons = atomic number = 16

  Number of neutrons + number of protons = 32 ⇒ Number of neutrons = 16

  Atomic specie = Sulfur

3. Mass number = 24

  Number of electrons = number of protons = atomic number = 12

  Number of neutrons + number of protons = 24 ⇒ Number of neutrons = 12

  Atomic specie = Magnesium

4. Mass number = 2

   Number of protons = atomic number = 1

   Number of electrons = 0

  Number of neutrons + number of protons = 2 ⇒ Number of neutrons = 1

  Atomic specie = Deuterium

5. Mass number = 1

   Atomic number = number of proton = 1

   Atomic specie = Hydrogen ion