Classification of Matter
How do atoms combine to make different types of matter?
Why?
Look at the things in this room. They are all matter. That matter may be pure or it may be a mixture. Can
you tell by looking at it? What if you looked at it under a microscope? Then could you tell? Something that
looks pure may not really be pure. It depends on what type of particles that thing is made of. In this activity
we will explore how the smallest chemical units of matter determine whether something is classified as an
element, a compound, or a mixture.
Model 1
R
T & RSq & R
?
?
RSq molecule
Sq2
molecule
atoms
atom
8 particles
molecule
5 particles
?
TSq2R
SqR3 & TSq
5 particles
!HSPI – The POGIL Project
Limited Use by Permission Only – Not for Distribution
vM - Classification of Matter C1Y
1
Atoms, Molecules, Particles & Chemical Formulas
1. Atoms & Molecules
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a) Circle a molecule of RSq in Model 1.
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b) How many atoms are in a molecule of RSq?
2. Atoms & Molecules
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a) Circle a molecule of TSq2R in Model 1.
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b) How many atoms are found in a molecule of TSq2R?
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c) How many Sq atoms are in a molecule of TSq2R?
3. Atoms & Molecules
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a) How many total molecules are shown in the drawing of SqR3 & TSq?
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b) How many total atoms are shown in the drawing of SqR3 & TSq?
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c) How many different types of molecules are found in a mixture of SqR3 & TSq?
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d) How many different types of atoms are found in a sample of SqR3 & TSq?
5. Particles
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a) How many particles are in the diagram of the sample of “R”?
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b) How many particles are in the diagram of the sample of “SqR3 & TSq”?
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c) Why does the drawing of “SqR3 & TSq” have only 5 particles, even though
there are 14 atoms in the picture?
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d) Can a particle be a single atom? !
e) Can a particle be a molecule?
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f) How many particles are in the drawing of T & RSq & R ?
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g) As a group, agree on a definition of the word “particle”, as it is used in
chemistry.
6. Chemical Formulas
Compare the formulas listed at the top of each diagram with the shapes in the box.
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a) What do the letters R, Sq and T in the codes represent?
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b) What do the small numbers (the subscripts) in the codes represent?
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c) When atoms are bonded in a molecule, how is that communicated in the
formula?
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d) When atoms or molecules are not bonded, how is that communicated in the
code?
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e) There are three drawings that are labeled “?”. Write codes to properly label
these drawings.
7. Chemical Formulas
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a) Why would the formula “3T & 3RSq & 2R” be a better formula for the “T & RSq
& R” drawing?
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b) Following the same pattern, what would be a better formula for the “SqR3 &
TSq” drawing?
8. Pure Substances & Mixtures
Read This! Matter is classified as a pure substance when all of the particles are the
identical. Matter is classified as a mixture if there are different particles present.
a) Sort the drawings into pure substances and mixtures. List the formulas for each set
here.
Pure Substances!!
____________ ____________!
____________ ____________!
____________ ____________!
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Mixtures
____________
____________
____________
b) How are the chemical formulas for pure substances different from those for mixtures?
8. Elements & Compounds
Read this! Elements are pure substances made from only one type of atom.
Compounds are pure substances made from two or more types of atoms.
a) Sort the pure substances into compounds and elements. List the formulas for each
set here.
Elements! !
____________ !
____________ !
____________ !
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Compounds
____________
____________
____________
b) How are the codes (chemical formulas) for elements different from those for
compounds?
9. Actual Chemicals
Key:
Br = Bromine!!
O = Oxygen! !
Na = Sodium!!
Cu = Copper! !
H = Hydrogen!
Zn = Zinc!
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C = Carbon
Al = Aluminum
a) Apply what you’ve just learned to write formulas for these “actual chemicals”.
H O
H
H H
Na
Na
Al
Al
Al
H
H
Al
H
O
H
Na
Al
Al
_______________
_______________
________________
b) How many molecules are in the first drawing in question (a)?
c) How many particles are in the first drawing in question (a)?
d) Are any of the drawings in question (a) an element? Which one?
e)Identify whether each of the following is a compound, mixture or element.
a. Br2!!
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b. NaHCO3 ! !
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c. C6H12O6 & H2O !
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d. Cu & Zn
e. CO2
f. Al
Al