Electrostatics
Learning Center #2
Building a model of an atom
CPO Science kit—Model of atomic structure
Instructions and background information for the game
Objectives:
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Be able to construct a model of an atom
Predict the charge on various atoms
Predict which atoms would gain electrons
I can find two or more pieces of data from a table or graph
I understand scientific words and vocabulary
I can read effectively in order to find information in paragraph
Station #2: Build a Model of an Atom
Atoms are the tiny building blocks from which matter is made. The various kinds of matter we find around us,
such as iron or oxygen, are made from different kinds of atoms. Atoms themselves are made of three basic
particles; electrons (negative), protons (positive), and neutrons (neutral). The protons and neutrons are
concentrated in a tiny space at the center of the atom called the nucleus.
By looking at the periodic table, you can tell how many protons, neutrons, and electrons an atom will have.
The atomic number determines how many protons (+) an atom will have. For this activity, you can assume
that the number of protons, neutrons, and electrons are equal. For example:
The atomic
Number for
Krypton is 36
That means
Krypton has 36
protons, neutrons,
and electrons
Atomic mass
The electrons can be found orbiting outside the nucleus. Electrons travel in spaces called “orbitals” which are
depicted as rings around the nucleus in the game you will play today. As atoms get more complex, they have
more protons, neutrons, and electrons. The electrons begin filling the orbitals closest to the nucleus first.
Generally speaking, the orbitals closest to the nucleus must be completely filled up before electrons will start
filling up orbitals farther away.
Atoms are stable when their outermost orbtials are completely filled. Atoms with half-filled orbitals will either
steal electrons from another atom, or give their electrons away.
Things to remember:
 Atoms whose orbitals are almost filled will gain electrons
 Atoms whose orbitals are mostly empty will lose electrons
 The number or protons and neutrons will not change. (It takes a nuclear reaction in order for that to
happen)
 If an atom has 2 more protons than electrons, the charge will be +2
 If an atom has 1 more electron than protons, the charge will be -1
If an atom
Gains electrons
It’s charge is
Negative
Loses electrons
Positive
Station #2: Build a Model of an Atom
Because
It now has more electrons
(-) than protons (+)
It now has more protons (+)
than electrons (-)
Build each of the atoms on your handout using this technique:
1. Look at the periodic table and decide how many protons, neutrons, and electrons that atom has.
2. Put all of the protons and neutrons in the nucleus.
3. Start placing the electrons in the orbitals, starting with the orbital closest to the nucleus and moving
outward.
4. Double check to make sure you placed the correct number of electrons, protons and neutrons. Make
sure each of the interior orbitals are filled before you start filling the next one.
5. Complete Learning station #2 handout.
Station #2: Build a Model of an Atom
Electrostatics Learning Station #2
Build a Model of the Atom
Name________________________
Date______________
Use the atomic models and the background information to fill in this table.
Element
# protons
# neutrons
# electrons
Gain or lose
electrons?
How many?
Charge
Lithium
Sodium
Chlorine
Fluorine
Magnesium
Aluminum
Oxygen
Which elements are most likely to steal electrons? Why?
Electricity is the flow of electrons. Atoms that have a positive charge tend to be good conductors of
electricity. Explain why this might be so.
When you rub a piece of rabbit fur on a rubber rod, the rod becomes negatively charged. What happened to
the electrons? Which object gained them and which one lost electrons?
Why can electrons be moved from one place to another, but protons cannot?
Station #2: Build a Model of an Atom