We use cookies to provide you with a great user experience. By using our site, you accept our use of cookies. You can review our cookie and privacy policy here.
  • Service & Support

    Contact Us

    Our Customer Service team is available from 8am to 6:00pm, ET, Monday through Friday. Live chat is available from 8am to 5:30pm ET, Monday-Friday.

    Email Customer Service
    Live Chat

    International Sales & Service

    We serve educators in more than 170 countries worldwide. Create a quote request on our website or contact our International Sales Team.

    International Ordering
  • Shopping

    Login or register now to maximize your savings and access profile information, order history, tracking, shopping lists, and more.

  • Quick
  • My Cart

    My Cart

    Your Shopping Cart is currently empty. Use Quick Order or Search to quickly add items to your order!

Determining Planck's Constant with LEDs: Investigating the Photoelectric Effect and Electronic Light Sensors Kit

(in stock)


Grades 9–12. In 3 experiments, students determine the wavelength of 4 LED colors and construct a circuit to find the threshold voltage of the LEDs. This is used to calculate frequency and energy, and to generate a mathematical model for Planck's constant.

PE: HS-PS4-3
Related PE: HS-PS3-3
Time Requirement: 90 minutes

SEP: Using Mathematics and Computational Thinking
CCC: Systems and System Models
DCI: HS-PS4.B Electromagnetic Radiation

Take a smartphone selfie, walk through an automatic door, or turn on your television with a remote, and you're using light sensors based on the photoelectric effect. In this comprehensive kit students:

  • Investigate light sensors and the photelectric effect
  • Build circuits to determine Planck's constant
  • Learn how light-emitting diodes (LEDs) and transistors function

Students establish relationships among light frequency, wavelength, and energy for LEDs while collecting data to calculate Planck's constant. Investigate the wave and particle models of light as students calculate threshold voltages to turn on LEDs (photoelectric effect) and calculate wavelength using a diffraction grating. The photoelectric effect and the discrete nature of quantum mechanics are addressed, laying the foundation for this lab.

Activities are designed for 4 groups working in 4 student teams. FREE 1-year access to digital resources that support 3-dimensional instruction for NGSS included.

The activities in this kit build toward the following Performance Expectations of the Next Generation Science Standards*: HS-PS4-3, HS-PS3-3. This kit is designed to integrate into a larger unit of lessons addressing wave mechanics, electricity, magnetism, and electromagnetism.

*Next Generation Science Standards® is a registered trademark of WestEd. Neither WestEd nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of this product, and do not endorse it.


What’s Included:
Needed But Not Included:
Return Policy:

If for any reason you are not satisfied with this item, it is eligible for a return, exchange, refund, or credit up to 180 days from date of purchase. Restrictions may apply. Returns & Exchanges Policy.

Recommended Accessories

Recommended Accessories

Meterstick, Plain Ends

Item #702620


Qty Discount Available

Quick View

Wire Stripper

Item #756525


Quick View