Chemistry · Structure of atom · chapter 2 of 9
Class 11 Chemistry Chapter 2: Structure of Atom Assertion-reason questions with answers
2 assertion-reason questions on Structure of Atom, each with its answer and the reason, written from the NCERT chapter. For school exams on the CBSE pattern, JEE Main and NEET, which are set from the same NCERT chapter. Open a question's solution to check your working; then take the free test to find your next chapter. Each question gives an Assertion (A) and a Reason (R); choose how they stand to each other.
Question 1
Assertion (A): 3517Cl and 3717Cl show the same chemical behaviour. Reason (R): Chemical properties are controlled by the number of electrons, which is fixed by the number of protons in the nucleus.
Show answer
Answer: (a) Both A and R are true, and R is the correct explanation of A.
Both are true. The two isotopes differ only in neutrons, which have very little effect; both have 17 protons and so 17 electrons, which is exactly why they react alike.
Question 2
Assertion (A): Electromagnetic radiation can travel through a vacuum. Reason (R): The electric and magnetic field components of an electromagnetic wave oscillate in planes perpendicular to each other.
Show answer
Answer: (b) Both A and R are true, but R is not the correct explanation of A.
Both are true, but the perpendicular arrangement of the fields is not why the wave needs no medium; R describes the wave, it does not explain A.
← Chapter 1: Some Basic Concepts of ChemistryChapter 3: Classification of Elements and Periodicity in Properties →