Light Energy

Approach

Do it:

Students engage in hands-on activities, such as testing which materials transmit light. Students also use mirrors to investigate reflection.

Talk it:

Students are provided with many opportunities for small group discussions to help them make sense of science ideas. For example, students discuss how light interacts with materials, and make the claim that all materials reflect light.

Read it:

Students read nine science books, including Why Do Scientists Disagree? about how scientists work together and communicate to move science forward. Students use comprehension strategies such as summarizing, and learn how to navigate informational text.

Write it:

Students write summaries and scientific explanations including a scientific explanation that answers the question, "Do non-shiny things reflect light?" Throughout the unit, students write to record observations and reflect on their learning.

Student Books

Learning Goals

Science Content

The Light Energy unit immerses students in the study of light. Students learn about the characteristics of light, investigate different ways light interacts with materials, and learn basic ideas about energy and about light as energy.

Characteristics of light: Students learn that all light is emitted from a source, and that light always travels in a straight line. Students also learn that light travels extremely fast- faster than anything else. Light is necessary for people to see things. Someone sees an object when light reflects off the object and travels to the person’s eye. White light is a mixture of many colors and can be separated into these different colors. When different colors of light mix, they make new colors.

Light interactions: Light interacts with materials in many ways including reflection, transmission, absorption, and refraction. Reflection is when light is blocked and bounces off a material. All visible materials reflect light. Transmission is when light passes through an object. Different materials transmit different amounts of light- from none to most of the light that hits the material. Absorption is when a material takes in light and does not allow it to pass through. All materials absorb at least some light, and usually become warmer when they do. Refraction is when light is transmitted and shifts direction at the boundaries of the material. Lenses, for example in cameras, eyes, and magnifiers, make use of refraction.

Light as energy: Students learn that energy can exist in many different forms, one of which is light. Students also learn about sound energy, chemical energy, electrical energy, thermal energy (heat), and motion energy. One form of energy can transform into another; for example, rubbing your hands together transforms motion energy into thermal energy. Students learn that light energy can transform into thermal energy when light is absorbed, and that darker materials absorb more light. Students learn that light energy from the Sun (solar energy) can be transformed into thermal or electrical energy and used in many ways.