Developmental Lesson: Distribution of electrons around the
nucleus
Teacher notes
Materials:
Student handout
Tape or sticky dots
Tape to make a grid on the floor (optional)
Timer for the teacher
Graph paper (optional, for students to use if there is no grid on the floor)
“Rewards” to place in the center of the “atom” (e.g. candy)
Notes to teacher:
Before getting started, ask the students about their beliefs regarding where electrons are in the
atom. Responses will range from in the nucleus, to outside the nucleus to orbiting around the
nucleus like planets. Ask them how electrons move in the atom. Answers will range from
spinning on their axes like planets to orbiting in paths like planets, to they don’t move they hover
in clouds. Record their response on the board or overhead for future reference. Then perform
activity.
In this activity, students move around the classroom as if they were electrons in an atom. A grid
pattern using chalk, tape or the floor tiles is set up before they get started and as the electrons
move around the student, a timer stops the students and they record their location on map of the
grid pattern.
Alternatively, they can do the activity without a grid, and put a piece of tape or a sticky dot on the
floor every time they stop. The students can estimate their location on a piece of graph paper.
After a couple of runs, add an attraction (bowl of something “rewarding” for the students) to the
center and repeat activity instructing the students to collect the items (one at a time) from the
center as they continue to move. Have students note the change in behavior of the electrons.
Ask student about how the model that they have just carried out is like and not like the electrons
in an atoms. Focus on the parts of the model of the atom.
1)
Ask students “where did you go on your third move?” “How about the path you took?”
Do you remember? Why not? ANS: Answers vary but the idea is that movement is
random so it is hard to trace an exact path
2)
List two things you did to mimic the repulsive behavior of an electron? ANS: kept moving
and tried to stay away from the others but still trying to go to the middle
3)
How did we model the attraction of the electron to the nucleus? Is this a good model—why
or why not? ANS: we had candy! Maybe not a good model cause kids stayed around the
nucleus. But isn’t this true of electrons? YEAH but they have more momentum and the
others would push them away.
4)
How did we model repulsions between electrons? Was there a difference between the two
trials? (Check colors on paper.) We were told to stay away from each other, stay in your
own square
Developmental Lesson: Distribution of electrons around the
nucleus
Teacher notes
5)
Were there truly repulsions between students? Did you feel it? Why? Was this a good
model—why or why not? I did not feel any repulsion and I often got too close to others.
6)
Did you find the objects in the middle an attraction of a distraction? Did it help the model
or hinder it? I think it was a distraction but it was definitely an attraction. Not for me I
don’t like skittles.
7)
When you add an attraction to the center of the atom does it change the path of the
electron? It definitely changes the path. I spent a lot more time in the middle or trying to
get to the middle than when there was nothing there.
8)
What happens if you limit the kids to only one kid per square? Does that help to show the
repulsions? I think it helps with the repulsions but it makes the path more organized so it is
not as random. Electrons don’t look for squares.
9)
Name 3 ways we could change our model to better demonstrate electron behavior? Student
answers were: hold hula hoops to repel the other electrons, make the squares bigger, do
something with magnets, limit people one per square, less distractions in the middle but
maybe a rubber band type attraction, maybe a goal to pick up 3 cards in the middle instead