Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : Energy of 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium.
Reason R: Energies of the orbitals in the same subshell decrease with increase in the atomic number.
In the light of the above statements, choose the correct answer from the options given below.
Assertion A : Energy of 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium.
Reason R: Energies of the orbitals in the same subshell decrease with increase in the atomic number.
In the light of the above statements, choose the correct answer from the options given below.
- (A)Both and are true and is the correct explanation of .✓ Correct
- (B)Both and are true but is NOT the correct explanation of .
- (C) is true but is false.
- (D) is false but is true.
Answer: (A)
Solution
For hydrogen (Z=1), the 2s orbital energy is eV. For lithium (Z=3), the 2s orbital experiences greater nuclear attraction due to higher atomic number, so its energy is more negative (lower). Therefore, the 2s orbital of hydrogen has greater (less negative) energy than that of lithium.
The reason correctly explains this: orbital energies in the same subshell decrease (become more negative) with increasing atomic number due to increased nuclear charge.
Both A and R are true, and R correctly explains A. The answer is (A).
The reason correctly explains this: orbital energies in the same subshell decrease (become more negative) with increasing atomic number due to increased nuclear charge.
Both A and R are true, and R correctly explains A. The answer is (A).
JEE Main · 2022 · 27 Jul 2022 · Shift 1 · Single correct option