Activity: Identifying Light Energy by Temperature Changes

Days Needed: 1
Grade level: 9 – 12

Objectives

Students will determine the amount of heat energy (infrared light) released from a burning peanut. The students will relate this experiment to a microcalorimeter.

Science and Math Standards

NCTM

  • Content Standard 2
    • Mathematics as Communication
  • Content Standard 4
    • Mathematical Connections

NSES

  • Content Standard A
    • Abilities necessary to do scientific inquiry
    • Understandings about scientific inquiry
  • Content Standard B
    • Structure of Atoms
    • Interactions of energy and matter
  • Content Standard F
    • Science and Technology

Prerequisites

  • Science Students should understand that light is a form of energy, and the basics of the electromagnetic spectrum. Students should understand what a spectrum is.
  • Math Students should be able to take measurements and use equations to calculate values.

Introduction

Students will explore hands-on how light energy can cause a change in temperature (in this case, in a flask of water). Students will relate what they find in this activity to how a microcalorimeter works to produce a spectrum of light from an incoming source. The microcalorimeter functions as energy dispersive x-ray detectors. This device picks up the energies of individual x-ray photons. The microcalorimeter is a sensitive thermometer that precisely measures the temperature variations due to the absorption of individual photons. Because it can measure very tiny temperature changes, this device will allow for the collection of spectra with extremely high-energy resolution, which will allow the measurement of chemical shifts due to different chemical bonding states, and the precise identification of incident photons.

Exploration

Materials:

  • paper clip
  • peanut
  • small aluminum pan
  • flask
  • ring stand and clamp
  • aluminum can with both ends open
  • thermometer

Print out the Student Worksheet for the class. Have them do the activity – the teacher should have a class discussion to go over the answers to the “Answer This” question.

Evaluation

Formative assessment and observation should be evident throughout the lesson. The worksheet, final questions during closure or a future quiz may serve as summative assessment.

Closure

Ask students to take three minutes to write what they have found in this experiment, and to relate this knowledge to how a microcalorimeter works. What would limit the microcalorimeter’s ability to produce a superior spectrum? What characteristics of a microcalorimeter make it an advance in spectrometer technology?