Chemistry Unit 1
Scientific Notation Homework: The Scale of the Universe
Use the animation at http://htwins.net/scale2/ to answer the following questions. This
investigation will focus on very small things—you are encouraged to explore the other end of the
spectrum on your own.
Developing a Sense of Scale
1. Scroll through the animation and choose an item measured in each unit to record in the
table below.
Item
Measurement
Unit
meters
Size (in given
unit)
Size (in meters)
m
centimeters
cm
millimeters
mm
micrometers
μm
nanometers
nm
picometers
pm
femtometers
fm
2. Make a note of some limits:
a. What is the smallest size object visible to the human eye? _____________________
b. What is the smallest size object visible to an optical microscope? _______________
Putting Atoms in Perspective
3. Which is larger, an atom or a molecule? Support your answer with quantitative evidence
from the animation.
4. Go back through the animation and find the size of
a. A carbon atom _____________________
b. A red blood cell ____________________
c. A piece of pencil lead ________________
5. Using you answers to the previous question,
a. How many times larger is a red blood cell than a carbon atom?
b. Zoom up to find something that many times larger than a human.
c. How many times larger (approximately) is a piece of pencil lead than a carbon atom?
d. Zoom up to find something that many times larger than a human.
6. Describe three different, accurate ways you could describe the size of an atom. These can
include measurements, comparisons, analogies, etc. (If you’re stuck, you can also get ideas
from this video: http://ed.ted.com/lessons/just-how-small-is-an-atom)