Chapter 4: Structure of Atom- Exercise- 52 B

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Chapter 4: Structure of Atom

Class: IX

Exercise number 52 B

 

Question 1

If number of electrons in an atom is 8 and number of protons is also 8, then

(i) what is the atomic number of the atom and

(ii) what is the charge on the atom?

Answer 1

(i) The atomic number is equal to the number of protons. Therefore, the atomic number of

  the atom is 8.

(ii) Since the number of both electrons and protons is equal, therefore, the charge on the

  atom is 0.

Question 2

With the help of Table 4.1, find out the mass number of oxygen and sulphur atom.

Answer 2

Mass number of oxygen = Number of protons + Number of neutrons = 8 + 8 = 16

Mass number of sulphur = Number of protons + Number of neutrons

= 16 +16 = 32