Chemistry Unit Practice Test
(2012-2013)
Match each science term to its proper definition.
1. Atom
a. A substance where
the particles are
mixed together
but not chemically
combined.
2. Mixture
b. A substance made
up of two or more
atoms.
3. Element
c. The smallest part
of an element that
still has the
properties of that
element.
4. Compou
d. A substance made
nd
up of two or more
different types of
atoms.
5. Molecule
e. A substance made
up of only one
type of atom.
6. What statement can be used to describe
what we currently know about the atom?
a. Atoms make up everything living
and non-living.
b. All atoms of one element are
identical to one another.
c. Atoms of different elements are
different from one another.
d. Compounds are formed when two
or more different kinds of atoms
bond together.
e. All of the above.
7. Why might the way we view the atom change
over time?
a. Scientists have become smarter
throughout human history.
b. Advances in technology have helped us
improve upon our designs.
c. The atom itself has changed shape
throughout human history.
d. The way we view the atom has not
changed.
8. Because the atom is so small,
a. we do not know what the atom truly
looks like.
b. they cannot be man-made.
c. scientists must create models to
help visualize and describe them.
d. they cannot be made up of smaller
particles.
Use the following diagram to help you answer
questions #9-13.
9. The atom is mostly made up of
_____________.
a. protons
b. neutrons
c. electrons
e. empty space
10. The sub-atomic particles found within the
atom are
a. protons.
b. neutrons.
c. electrons.
d. all of the above.
11. What sub-atomic particle is located at letter
“A”?
a. Proton
b. Neutron
c. Electron
d. Nucleus
12. Which particles exist in the atom’s nucleus
(Part “D”)?
a. Protons and neutrons
b. Protons and electrons
c. Neutrons and electrons
d. Neutrons, electrons and protons
13. Which of the following parts of the atom is
NOT correctly matched to its charge?
a. Proton: Positive
b. Neutron: Negative
c. Nucleus: Positive
d. Electron: Negative
Match each experiment with the discovery of the
atom that resulted.
14. Gold Foil Experiment –
A. The atom contains
shooting radioactive
negatively charged
particles at gold foil.
particles called
Some particles bounced
“electrons.”
back, some went through.
15. Cathode Ray Tube – shot
B. Electrons orbit the
electrically charged
nucleus in distinct
particles through
pathways called
magnetized plates. The
orbitals.
particles bent as they
moved through the plates.
16. Experimented with atoms C. Atoms make up
to see why electrons
everything in the
didn’t get pulled into the
universe, from solids,
nucleus. Found that
to liquids and even
electrons gave off or
gases.
absorbed energy in the
form of light as they
orbited the nucleus.
D. The atom is mostly
17. Hypothesized the
empty space; the
existence of the atom as
nucleus is a dense,
a building block for
positively charged
matter.
area in the center of
the atom.
18. The Periodic Table is a chart used to
a. organize the elements that make up
the world around us.
b. group elements based on similar
physical and chemical properties.
c. describe information about each of
the atoms in the universe.
d. all of the above.
19. Atoms on the Periodic Table are arranged
a. alphabetically.
b. by increasing atomic mass.
c. by increasing atomic number.
d. by date of discovery, or synthetic
preparation.
20. The elements in a Group/Family (column) of
the Periodic Table
a. have similar chemical symbols.
b. are in the same period.
c. have the same atomic mass.
d. have similar properties.
21. Which of the following families on the
Periodic Table would be the MOST
reactive?
a. Noble Gases
b. Transition Metals
c. Alkali Metals
d. Metalloids
22. The element Scandium has an Atomic Mass
of 45, and an Atomic Number of 21. Which
of the following accurately describes the
number of protons, neutrons and
electrons?
a. Protons = 21, Neutrons = 21,
Electrons = 21
b. Protons = 45, Neutrons = 21,
Electrons = 45
c. Protons = 21, Neutrons = 24,
Electrons = 21
d. Protons = 45, Neutrons = 24,
Electrons = 45
23. Which element is represented by the
symbol “N”?
a. Nitrogen
b. Neptunium
c. Neodymium
d. Nickel
24. What holds atoms together in a molecule or
a compound?
a. Density
b. Gravity
c. Chemical bonds
d. Physical bonds
25. Which of the following is an example of an
element?
a. Milk
b. Oxygen
c. Air
d. Carbon dioxide
26. Which of the following is a compound?
a. Salt (NaCl)
b. Water (H2O)
c. Sugar (C6H12O6)
d. All of the above
27. Which of the following elements is NOT
found in a strand of DNA?
a. Hydrogen
b. Oxygen
c. Nitrogen
d. Helium
28. Which of the following statements is FALSE
about the DNA molecule?
a. It is a macromolecule made up of
thousands of atoms.
b. It has a sugar-phosphate backbone.
c. It takes the shape of a single helix.
d. It is composed of the base pairs A-T
and C-G.
Use the following scenario to help you answer questions
#29-30.
A chef is baking a cake for a birthday party. She mixes
together the flour, sugar, salt, baking powder, milk and
eggs, then pours her mixture into a cake pan. She then
puts the pan into the oven, and lets it bake for 30
minutes at 350°F.
29. How would you classify the type of mixture the
chef would have after she mixes together all of
her ingredients?
a. Heterogeneous mixture – you can
see all the individual parts of the
mixture.
b. Heterogeneous mixture – you
cannot see all the individual parts of
the mixture.
c. Homogeneous mixture – you cannot
see the parts of the mixture because
they are too well mixed.
d. Homogeneous mixture – you can
see all the individual parts of the
mixture.
e. A solution – the ingredients are all
dissolved in one another.
30. What type of change is happening to the
cake as the chef bakes it in the oven?
a. A chemical change.
b. A physical change.
c. Freezing.
d. Melting.
31. What is “solubility”?
a. The ability for an object to dissolve
another object.
b. The ability for an object to be
dissolved.
c. The ability for an object to resist
acids.
d. The ability for an object to resist
bases.
32. How is a solute different from a solvent in a
solution?
a. The solute is dissolved in the
solvent.
b. The solvent is dissolved in the
solute.
c. The solute is always a liquid and the
solvent is always a solid.
d. The solvent is always a liquid and
the solute is always a solid.
33. A student mixes a packet of Kool-Aid
powder with water. In their mixture,
a. The Kool-Aid powder is the solute,
and the water is the solvent.
b. The Kool-Aid powder is the solvent,
and the water is the solute.
c. The Kool-Aid powder and water are
both solutes.
d. The Kool-Aid powder and water are
both solvents.
34. If you have a solution of Kool-Aid and
water, how could you separate this mixture
to get the Kool-Aid powder back?
a. Magnetism
b. Chromatography
c. Evaporation
d. Filtration
35. The process of filtration separates materials
through the use of a screen, coffee filter,
etc. What physical property of a material
allows the particles to be separated by the
filter?
a. Solubility
b. Magnetism
c. Color
d. Size
36. If you heat a liquid and measure the
temperature at which it melts, you are
measuring a(n)
a. atomic property.
b. physical property.
c. chemical property.
d. molecular property.
37. What is the “pH” of a substance?
a. The measure of how acidic or basic a
substance is.
b. The amount of hydrogen ions
present in the substance.
c. The amount of hydroxide ions
present in the substance.
d. All of the above.
38. You can find the pH of a substance by using
____________.
a. litmus paper
b. a thermometer
c. a conductivity tester
d. an Erlenmeyer flask
39. Acids are substances that have a high
concentration of H+ ions. What would the
ion H+ be classified as?
a. A cation, because it is positively
charged.
b. An anion, because it is positively
charged.
c. A cation, because it is negatively
charged.
d. An anion, because it is negatively
charged.
40. How many oxygen atoms are in the
following compound: Cu(NO3)2
a. 0
c. 2
b. 1
d. 3
Short Answer Questions
Please complete the following questions on the back of
your lined piece of paper.
41. Balance the following equation:
______
N2 + _____ H2  _____ NH3
42. What are the reactants? What are the
products?
43. Would the resulting molecule (NH3) be
covalent or ionic? How do you know?
44. Draw the Lewis Structure for the molecule
NH3.
45. Give the scientific name for the molecule
NH3.