Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709

An electron moves from an energy level of -8.6 eV to another level of -3.5...

Physics
WAEC 2023

An electron moves from an energy level of -8.6 eV to another level of -3.5 eV. Determine the frequency of the absorbed radiation. [1 eV = 1.6 × \(10^{19}\) J, h = 6.6 × \(10^{34}\) Js]

  • A. \( 2.93 \times 10^{15}\)Hz
  • B. \( 3.59 \times 10^{16}\)Hz
  • C. \( 5.39 \times 10^{15}\)Hz
  • D. \( 1.24 \times 10^{15}\)Hz
NECO June/July 2024 - Get offline past questions & answers - Download objective & theory, all in one app 48789
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
Correct Answer: Option D
Explanation

h = \( 6.6 \times 10^{-34}\)Js, 1eV =  \( 1.6 \times 10^{-19}\)J, \(E_1\) = - 8.6eV, \(E_2\) = - 3.5eV, f = ?

ΔE = hf 

f = \(\frac{ΔE}{h}\)

ΔE =  \(E_2\) -  \(E_1\) = - 3.5eV - (- 8.6eV) = 5.1eV

but 5.1eV = 5.1 X \( 1.6 \times 10^{-19}\) = \( 8.16 \times 10^{-19}\)J

f =  \(\frac{8.16 \times 10^{-19}}{ 6.6 \times 10^{-34}}\)

Therefore, f =  \( 1.24 \times 10^{15}\)Hz


Report an Error Ask A Question Download App
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
Join your school's WhatsApp group
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
Join your school's WhatsApp group
NECO June/July 2024 - Get offline past questions & answers - Download objective & theory, all in one app 48789
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
Join your school's WhatsApp group
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
NECO June/July 2024 - Get offline past questions & answers - Download objective & theory, all in one app 48789