set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

In an atom valence electron are present in

a) next to outermost orbit

b) first orbit

c) outermost orbit

d) any one of its orbit

Question : 2

The nucleus of an atom contains

a) electrons

b) protons and neutrons

c) protons

d) neutrons

Question : 3

Isotopes are those atoms of the same element which have

a) Atomic mass is different but atomic number is same

b) Atomic number and atoms mass both are same

c) Atomic mass is same but atomic number is different

d) None of the above

Question : 4

Match List-I with List-II and select the correct answer using the code given below the lists.

a) 3 2 4 1

b) 2 3 4 1

c) 2 3 1 4

d) 3 2 1 4