The two main branches of
science are
physics and chemistry.
natural and physical science.
natural and social science.
biological and earth science.
Which of the following is not a
branch of biology?
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geology
zoology
ecology
medicine
Technology can best be defined as
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science that uses computers.
applied science.
new inventions.
the use of lenses and microscopes.
For a scientific theory to be valid, it
must allow you to
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perform experiments.
obtain new results each time.
find a new, more complex explanation.
make predictions.
Each molecule of hydrochloric acid,
HCl, contains one atom of hydrogen
and
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one atom of chlorine.
one atom of oxygen.
two atoms of chlorine.
two atoms of oxygen.
Solid ionic compounds have very
high melting points because they
• are positively charged.
• contain metallic elements.
• are made of elements that are solid at
room temperature.
• contain charged ions that are locked tightly
together.
In which type of bond do atoms
share pairs of electrons?
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covalent bonds
metallic bonds
ionic bonds
polyatomic bonds
The first step in the scientific
method is usually
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making an observation.
forming a hypothesis.
collecting data.
testing a hypothesis.
The sample contained the same number
of pennies for which two years?
• 1988 and
1992
• 1988 and
1991
• 1994 and
1997
• 1994 and
1998
What is 78,900,000,000 expressed
in scientific notation?
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789 x 109
7.89 x 109
78.9 x 109
7890 x 109
A measurement that is accurate is
one that
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is as exact as possible.
is close to the true value.
contains at least four significant figures.
contains five decimal places.
A precise measurement is one that
• contains the correct number of significant
figures.
• contains at least three significant figures.
• is close to the true value.
• is as exact as possible.
The chemical formula for water, H2O,
means that each water molecule
contains
• two hydrogen atoms and two oxygen
atoms.
• two hydrogen atoms and one oxygen
atom.
• two hydrogen atoms and zero oxygen
atoms.
• one hydrogen atom and two oxygen
atoms.
The kinetic theory states that the higher
the temperature, the faster the
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particles that make up a substance move.
bonds between atoms break down.
molecules of gas rush together.
lighter particles within a substance clump
together.
You burn a log of wood, and only a small
pile of ashes is left. What has happened?
• A large amount of mass has been lost.
• A small amount of mass has been
converted into a large amount of heat
energy.
• The total mass of the wood and oxygen is
the same as the total mass of the ash and
gases.
• The total amount of energy is less than
before.
When water is broken down, what happens to
the oxygen and hydrogen atoms it is made of?
• They combine with oxygen in air to
produce new substances.
• They are rearranged to form hydrogen and
oxygen gas
• They are destroyed.
• They increase in size until they form a
solid.
Dalton's atomic theory was
accepted because
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there was evidence to support it.
Democritus said that it was correct.
Dalton invented the electron microscope.
Dalton showed how molecules are formed.
Which statement about the atomic
nucleus is correct?
• The nucleus is made of protons and
neutrons and has a negative charge.
• The nucleus is made of protons and
neutrons and has a positive charge.
• The nucleus is made of electrons and has
a positive charge.
• The nucleus is made of electrons and has
a negative charge.
Atoms have no electric charge
because they
• have an equal number of charged and
noncharged particles.
• have neutrons in their nuclei.
• have an equal number of electrons and
protons.
• have an equal number of neutrons and
protons.
Which statement about an element's
average atomic mass is correct?
• It is determined by counting the number of
isotopes in a sample of the element.
• It is equal to one-twelfth the mass of the most
common isotope.
• It is a weighted average, so common isotopes
have a greater effect than uncommon ones.
• It is based on an isotope's charge, so negatively
charged isotopes have a greater effect than
positive ones.
An atomic mass unit is equal to
Bonus-5 points
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one-half the mass of a hydrogen atom.
one-fourth the mass of a lithium atom.
one-twelfth the mass of a carbon-12 atom.
one-fifteenth the mass of a nitrogen-15
atom.
Which statement about the alkali
metals is correct?
• They are located in the left-most column of
the periodic table.
• They are extremely nonreactive.
• They are usually gases.
• They form negative ions with a 1– charge.
Alkali metals are extremely reactive
because they
• have very small atomic masses.
• are not solids at room temperature.
• have one valence electron that is easily
removed to form a positive ion.
• have two valence electrons that form
compounds with calcium and magnesium.
Which statement about noble
gases is correct?
• They form compounds with very bright
colors.
• They exist as single atoms rather than as
molecules.
• They are highly reactive with both metals
and nonmetals.
• They are extremely rare in nature.
Semiconductors are elements that
• have large atomic masses but small
atomic numbers.
• do not form compounds.
• can conduct heat and electricity under
certain conditions.
• are extremely hard.
Most halogens form compounds by
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gaining an electron to form a negative ion.
losing an electron to form a positive ion.
losing protons.
joining with both calcium and carbon.
Transition metals such as copper or
tungsten form compounds by
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gaining electrons to form negative ions.
losing electrons to form positive ions.
losing neutrons.
changing shape and color at various
temperatures.
Molar mass is defined as
Bonus-5points
• the number of particles in 1 mole of a
substance.
• the SI base unit that describes the amount
of a substance.
• the amount of a substance necessary to
have a positive charge.
• the mass in grams of 1 mole of a
substance.
A compound differs from a mixture
because it
• always remains frozen even at high
temperatures.
• is formed from two cations.
• always contains the same elements in the
same proportion.
• can form only in the presence of heat
energy.
Gases take up a lot of space
because
• they have weak chemical bonds.
• their molecules have very little attraction
for one another.
• they contain very few atoms.
• they have a small molar mass.
Often atoms join so that each atom
will have
• an even number of electrons.
• an outermost energy level that is full of
electrons.
• an equal number of protons and electrons.
• more electrons than either protons or
neutrons.
An ionic bond is a bond that forms
between
• ions with opposite charges.
• atoms with neutral charges.
• one atom's nucleus and another atom's
electrons.
• the electrons of two different atoms.
Copper is a good conductor of
electricity because its electrons
• are positively charged.
• are free to move from atom to atom.
• can take on either positive or negative
charges.
• are shared between neighboring
compounds.
Solid ionic compounds have very
high melting points because they
• are positively charged.
• contain metallic elements.
• are made of elements that are solid at
room temperature.
• contain charged ions that are locked tightly
together.
The name dinitrogen tetroxide tells you
that this compound contains
• two nitrogen atoms and two oxygen
atoms.
• four nitrogen atoms and two oxygen
atoms.
• two nitrogen atoms and four oxygen
atoms.
• four nitrogen atoms and four oxygen
atoms.
Putting lemon juice on a piece of
cut apple will
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make the fruit softer and easier to chew.
prevent the fruit from turning brown.
make the fruit taste sweeter.
neutralize the acid in the fruit.
Acids are substances that
• form hydronium ions when dissolved in
water.
• turn red litmus paper blue.
• make foods taste bitter.
• react with neutral liquids to form bases.
An unsaturated solution is one that
• can dissolve more solute at the current
conditions.
• will precipitate out all its dissolved solute.
• can dissolve more solute only if heated.
• can dissolve more solute only if the
pressure is increased.
Water is referred to as the universal
solvent because
• it is found throughout the universe.
• all known substances dissolve in water.
• many different substances dissolve in
water.
• it covers more than half of the Earth's
surface.
All of the following will make it easier to
dissolve a solute in a solvent except
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heating the solvent.
stirring the solution.
increasing the surface area of the solute.
adding a larger amount of solute.
Sugar will dissolve more quickly in iced
tea if you stir it because stirring
• absorbs kinetic energy.
• allows dissolved molecules to diffuse
through the tea.
• increases the solubility of the solution.
• changes the electric charges of the water
molecules.
Solubility refers to the
• size of the particles that make up a
substance.
• grams of solute per 100 g of solvent.
• number of moles of solvent dissolved per
liter of solution.
• concentration of a solute that is actually
dissolved in a solvent.
Distillation can be used to separate
solutions of miscible liquids because
• different liquids usually have different
boiling points.
• boiling breaks the chemical bonds within
each liquid.
• denser liquids sink to the bottom.
• solids remain after the liquids are boiled
away.
You can skim the fat off the top of a
kettle of cold soup because fat is
• made of small particles.
• less dense than water and rises to the top.
• an emulsion that remains dispersed
throughout the soup.
• made of large particles that will not pass
through a filter.
You can usually filter out solid
particles in a suspension by
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pouring the less dense liquid off the top.
boiling it so that the solids are left behind.
distilling the entire suspension.
using a paper filter to catch the particles.
At which time of day was the
temperature approximately 4ºC?
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9:00 A.M.
10:00 A.M.
11:00 A.M.
12:00 P.M.
The element that is most abundant
in Earth is
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iron.
oxygen.
silicon.
magnesium.
A lithium ion is much less reactive
than a lithium atom because it
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is much more massive.
has a full outermost energy level.
has a negative electric charge.
is in a different group in the periodic table.