Learning about Lenses
Objectives: To examine how light behaves and see how this affects how we see objects using lenses.
Materials:
Plastic slides (4 per group)
Pipet/water dropper
Student data sheet
Dixie cup with water
crayon
paper towels
Procedure:
1. Take one plastic slide and place it in the large box in the student work sheet
2. Use a crayon to draw a circle in the middle of the slide
3. Use the water dropper or pipet to add drops to the circle and fill it without the water spilling
over. Count as you fill it.
4. How many drops of water did you fit into the circle?_____________________
5. Look at your slide from the side and sketch it in side view in the space below:
6. How would you describe the shape of the water droplet on the slide:
_____________________________________________________________________________
7. Now move the slide to the lower corner of the box and observe the letters at the bottom of the
page. Describe what you see.
____________________________________________________________________________
8. Now lift the slide up, be careful not to spill the water, and look again at the letter. Describe how
the letters look compared to when you looked at them in step 7.
______________________________________________________________________________
______________________________________________________________________________
9. How did this water lens change what we see?
Student Work Area
Water
science
lense
magnifier
refraction
Teacher Notes
Concept Information
K-4 Light is an example of energy transformation (NGSS)
Light travels in a straight line until it strikes an object (NSES)
After it strikes an object it can be reflected, refracted or absorbed (AAAS)
Light can be reflected by a mirror, refracted (Bent into a new direction) by a lens, or absorbed by an
object. (AAAS)
5-8 Light interacts with matter by transmission – including refraction, absorption or scattering
(reflection) (NSES< NGSS)
Light is necessary for sight. We can only see objects as they reflect light back to our eyes. If that light is
bent by a transparent convex lens, the image appears magnified. For a person to see an object – light
from that object (either emitted or scattered from it) must enter the eye.
The curved outward shape the water will make on the slide is called Convex. A convex surface bends
the light in a manner that magnifies the object seen through it. This is how lenses magnify. A concave
shape is curved inward and will make the object appear smaller.
Materials tips:
1. Plastic slides work much better than glass slides.
2. Draw 2 consecutive rings to reinforce the boundary
3. Would a grease pen work better??
4. Have a paper towel at each station for eventual spills
5. Keep water in a stock pitcher by the teacher and pour into the Dixie cup just as you are getting
started.
6. Review how to use a pipet or dropper as many kids do not have experience with this. This also creates
an opportunity to reinforce that they have to count the drops. The drops will be related to how big the
original circle is.
Extensions: Test hand lenses as additional magnifiers and see if similar results are found.
Have students identify common lenses we use: glasses, telescopes, binoculars, microscopes.
Explanation and Evidence
Lenses have a flat surface that allows light to pass through in a straight line
Option 1. I agree with the statement because (cite your evidence)
Option 2. I disagree with the statement because (cite your evidence)
Option 3. I agree with part of the statement because (cite your evidence) but I disagree with
part of the statement because (cite your evidence)
Lenses have a curved surface that bends light as it passes through it
Option 1. I agree with the statement because (cite your evidence)
Option 2. I disagree with the statement because (cite your evidence)
Option 3. I agree with part of the statement because (cite your evidence) but I disagree with
part of the statement because (cite your evidence)