No products in the cart.

A hydrogen atom in its ground …

CBSE, JEE, NEET, CUET

CBSE, JEE, NEET, CUET

Question Bank, Mock Tests, Exam Papers

NCERT Solutions, Sample Papers, Notes, Videos

A hydrogen atom in its ground state is excited by means of monochromatic radiation of wavelength 975 Angstron.How many lines are possible in resulting emission spectrum?Calculate the longest wavelength among them. You may assume ionisation energy for hydrogen atom as 13.6eV.

Posted by Parth Makhija 2 years, 6 months ago

CBSE > Class 12 > Physics

1 answers

Preeti Dabral 2 years, 6 months ago

Energy of the ground state (n = 1) = – (ionization energy) = –13.6 eV
The wavelength of the incident radiation, $\lambda$ = 975 $\mathop {\text{A}}\limits^{\text{o}}$
$\therefore$ The energy of the incident photon = hc/ $\lambda$
= $\frac{6.63 \times 10^{-34} \times 3 \times 10^{8}}{975 \times 10^{-10} \times 1.6 \times 10^{-19}}$ = 12.75 eV
Let electron is exerted to nth orbit,
$\Rightarrow$ 12.75 = 13.6 $\left(\frac{1}{1^{2}}-\frac{1}{n^{2}}\right)$
$\Rightarrow$ n = 4
The quantum transitions to the less excited states gives six possible lines as follows:
n = 4 : (4 $\rightarrow$ 3), (4 $\rightarrow$ 2), (4 $\rightarrow$ 1)
n = 3 : (3 $\rightarrow$ 2), (3 $\rightarrow$ 1)
n = 2 : (2 $\rightarrow$ 1)
The longest wavelength emitted is for the transitions (4 $\rightarrow$ 3) where energy difference is minimum.
E_min = (E₄ - E₃) = 13.6 $\left(\frac{1}{3^{2}}-\frac{1}{4^{2}}\right)$ = 0.661 eV
Thus $\lambda_{\max }=\frac{h c}{\mathrm{E}_{\min }}$
= $\frac{6.63 \times 10^{-34} \times 3 \times 10^{8}}{0.661 \times 1.6 \times 10^{-19}} \mathrm{m}$
$\approx$ 18807 $\mathop {\text{A}}\limits^{\text{o}}$

ANSWER

http://mycbseguide.com/examin8/

Related Questions

A Carbon resistor has three strips of red colour and a gold strip. What is the value of resistor? What is its tolerance?

Posted by Kaviyarasan 2007 11 months, 2 weeks ago

CBSE > Class 12 > Physics

0 answers

Derivation of ohm's law class 12

Posted by Aniket Mahajan 4 months, 1 week ago

CBSE > Class 12 > Physics

0 answers

Lota graph showing the variation of current with voltage for the materials gaas on the graph mark the reason where a resistance is negative and Om is obey

Posted by Siwani Gupta 11 months ago

CBSE > Class 12 > Physics

0 answers

two pith -balls each weighing 10-³ kg are suspended from the same point by means of silk threads -0.5 m long .on charging the balls equally, they are found to repel each other to a distance of 0.2 m .calculate the charge on each ball .

Posted by Preeti Sahu 4 months, 1 week ago

CBSE > Class 12 > Physics

0 answers

A mirror is turned through 17 degree then the reflected ray is turned by

Posted by Khushbu Otti 11 months, 2 weeks ago

CBSE > Class 12 > Physics

0 answers

what us current

Posted by Shristi Maurya 4 months, 3 weeks ago

CBSE > Class 12 > Physics

2 answers

A pith ball may become charge d by gaining or losing

Posted by Anterpreet Kaur 1 year ago

CBSE > Class 12 > Physics

0 answers

Two metallic sphere of radii 1 cm and 3 cm are given charge of minus 1 into 10 ke power 2 coulomb and 5 x 10 power 2 respectively if these are connected by conducting wire the final charge on the bigger sphere is

Posted by Khushi Aw 11 months, 4 weeks ago

CBSE > Class 12 > Physics

0 answers

Three charges q,-4q,2q are placed at vertex of equilateral triangle find amount of work done to make its set up

Posted by Manshi Roll No-36,Class Xi-A 8 months, 3 weeks ago

CBSE > Class 12 > Physics

0 answers

Q.3A Free Proton and a Free Electron are Placed in a Uniform Field. Which of the Two Experiences Greater Force and Greater Acceleration?

Posted by Ayush Rajput 1 year ago

CBSE > Class 12 > Physics

1 answers

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Google Play

Download myCBSEguide App