Download Name: : :___ Building Atoms An atom is made of 3 particles. Name

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Building Atoms
An atom is made of 3 particles. Name those 3 particles and their charges.
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Key for Atom Model
yellow – electrons
blue – neutrons
red – protons
Part 1
1. Place 4 protons (red) in the center of the board. What is the total charge of the protons?
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2. Place 5 neutrons (blue) in the center of the board with the protons. Now what is the total
charge of the protons plus the neutrons? _______________________
3. Place 4 electrons in your hand. What is the total charge of those particles in your hand?
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4. Now, finish building the atom by adding the four electrons to the outer level on the board.
What is the total charge of the atom you just built? ________________
5. What is the name of the element you just built? _____________________________
6. Draw a picture (Bohr model) of the atom in the box below. Include all of the parts of the
atom, and label each part.
7. Fill in the table below.
Element
Atomic #
# of
Protons
# of
Electrons
Mass
oxygen
16
phosphorus
31
# of
Neutrons
8. Build a model of sulfur on your board. Raise your hand once you and your partner are
finished.
9. Draw a picture (Bohr model) of sulfur in the space below.
Part 2
What are isotopes?
Atoms of the same element can have different numbers of neutrons which in return makes
the element’s mass different; the different possible versions of each element are called
isotopes. For example, hydrogen has 2 isotopes. One has a mass number of “1” and is called
hydrogen-1. The other has a mass number of “2” and is called hydrogen-2.
How many isotopes can one element have? Can an atom have just any number of
neutrons?
No; there are "preferred" combinations of neutrons and protons, at which the forces holding
nuclei together seem to balance best. Lighter (not heavy) elements tend to have about as many
neutrons as protons; heavy elements apparently need more neutrons than protons in order to
stick together. Atoms with a few too many neutrons, or not quite enough, can sometimes exist
for a while, but they're unstable.
I'm not sure what you mean by "unstable." Do atoms just fall apart if they don't
have the right number of neutrons?
Well, yes, in a way. Unstable atoms are radioactive: their nuclei change or decay by spitting
out radiation, in the form of particles or electromagnetic waves.
Let’s Practice:
10. How many isotopes are in magnesium? ___________
11. How many isotopes does calcium have? ___________
12. How many neutrons does nitrogen-1 have? _____
What about nitrogen-2? ______
How many neutrons does copper-65 have? _____ How many protons does it have? _____
(It is still the same element, it just might have an extra neutron.)
13. Build a model of magnesium-26.
14. Draw a picture of this model in the space below.
Part 3
What are ions?
Ions are electrically charged particles. They form when an atom contains an unequal number
of protons in the nucleus and electrons in the electron cloud. They are nothing more than
atoms or molecules that have gained or lost an electron.
13. Place 9 protons, 10 neutrons, and 10 electrons on the atom model.
14. What atom is being represented on the board? _______________________
15. What is the total charge of this atom? ________________________
16. What is the mass of this atom? _____________________
17. What do you call an atom that has different numbers of protons and electrons? __________
18. What would you have to do to make this atom neutral? _________________________
19. Fill in the chart below.
Element
Atomic #
# of protons
# of electrons
hydrogen
0
berylium
4
boron
2
flourine
10
Total Charge
Is the atom an
ion?
20. What does it mean when an atom is neutral?
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21. What is the difference between an ion and an isotope?
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22. In order to make an element from another element, what would you need to do?
For example, how could you make a zinc atom from a copper atom?
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23. List 2 ways in which the atom building board is like a real atom and 2 ways it is not
like a real atom.
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24. Atoms of an element can have more than one mass number, but only one atomic
number. Why?
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25. Why is the periodic table of elements an important tool in science? List 2 reasons to
explain why the periodic table is so useful.
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