Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
+2 votes
16.8k views
in Physics by (34.4k points)

The wavelength of the photon emitted by a hydrogen atom when an electron makes a transition from n = 2 to n = 1 state is :

(1) 194.8 nm

(2) 913.3 nm

(3) 490.7 nm

(4) 121.8 nm

Please log in or register to answer this question.

2 Answers

+2 votes
by (34.9k points)

Correct option  is (4) 121.8 nm

\(\frac{1}{\lambda}=R(\frac{1}{1^2}-\frac{1}{2^2})\)

\(\lambda=121.8\) nm

+2 votes
by (60 points)
reshown by
ΔE = 10.2eV

hc/λ=10.2ev

λ =hc/(10.2)e

12400/10.2 Angstrom
= 121.56nm
≃ 121.8nm

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

...