NAME __________________________
LAB
ATOMIC STRUCTURE
PARTICLE
MASS
CHARGE
Proton
Neutron
Electron
INTRODUCTION
All the matter in the universe is made up of atoms; and all atoms are made up of only
three types of subatomic particles: protons, neutrons & electrons. Furthermore, all
protons are exactly the same, all neutrons are exactly the same, and all electrons are
exactly the same. Protons and neutrons have masses of about 1 atomic mass unit (amu).
Electrons have a mass that is about 1/2000 the mass of a proton/neutron. Electrons
are negatively charged. Protons are positively charged. Protons & electrons have
charges exactly opposite each other. Neutrons do not have any net charge (i.e., they
are neutral).
Protons & neutrons are in the center of the atom in a nucleus. Virtually all of the mass
of the atom is concentrated in the nucleus (because the electrons weigh so little). The
electrons are outside the nucleus in electron shells (orbitals). The nucleus only takes up
about one trillionth of the total space of the atom. The atom is mostly empty space.
Atoms with different numbers of protons have different chemical properties. We
identify these different types of atoms as different elements. Since the negative
electrons are attracted to the positive protons, neutral atoms have the same numbers
of protons & electrons. The number of neutrons in the nucleus, however, can vary.
When atoms of the SAME element have a DIFFERENT number of neutrons, these atoms
are called isotopes.
In this lab, you will be using different types of seeds to represent the different
subatomic particles. You will use white beans to represent protons, black-eyed peas to
represent neutrons, and poppy seeds to represent electrons. "White" represents a
positive charge, "black" represents a negative charge, and "mixed" represents a neutral
charge. You will determine the number of protons & electrons from the accompanying
periodic table. The number of neutrons will have to be determined from the isotope
numbers given. Since the mass of protons & neutrons are each about 1 amu, assume
that the mass of each bean/pea is 1 amu. The mass of the poppy seeds is almost zero,
so we don’t have to count it in our calculations.
MATERIALS
 Bean seeds (white), black-eyed peas, poppy seeds, glue
METHODS
 Use the separate packet to construct each of the 8 atoms/isotopes listed. Use glue
to place the appropriate number of PROTONS (white bean seeds) & NEUTRONS
(black-eyed peas) in the center of the atom. Circle this group of subatomic particles
in pencil to indicate the nucleus.
 Use glue to place the appropriate number of ELECTRONS (poppy seeds) in their
proper orbitals (energy levels). Remember, the 1st orbital can only hold a maximum of
2 electrons while the 2nd & 3rd orbitals can hold a maximum of 8 electrons.
 Have your teacher initial your results to indicate accurate completion.
 Complete the results table below & answer the discussion questions that follow.
RESULTS
 Teacher Initials
________
Data Table
Atom/Isotope
1
H1
1
H2
2
He4
C
6 12
C
6 14
7
N14
8
11
O16
Na23
# of Protons
# of
Neutrons
# of
Electrons
Atomic Mass
(amu)
# of Valence
Electrons
DISCUSSION
1. How many neutrons are present in the 1H1 atom? ______
2. How does the addition of a neutron (black-eyed pea) alter the mass of the 1H1 atom?
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3. What is the definition of an isotope? Give an example.
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4. What is the difference in subatomic particles between the isotopes 6C12 & 6C14?
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5. Draw the atomic structure for a Neon (Ne) atom in the space below. Label the
protons, neutrons & electrons.
6. What isotope has 12 protons, 14 neutrons & 12 electrons? What is this element's
"normal" number of neutrons?
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7. In the space below, draw the atomic structure of
12
Mg24
8. Since O (oxygen) has 6 valence electrons, do you think O would react readily with
magnesium (Mg)? Explain!
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1
H1
1
H2
2
He4
C
6 12
C
6 14
7
N14
8
O16
11
Na23