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?
• geology
• zoology
• ecology
• medicine
Technology can best be defined as
• 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
• 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
• 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?
• covalent bonds
• metallic bonds
• ionic bonds
• polyatomic bonds
The first step in the scientific method is usually
• 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?
• 789 x 109
• 7.89 x 109
• 78.9 x 109
• 7890 x 109
A measurement that is accurate is one that
• 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
• 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
• 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
• 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.
Bonus-5 points
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
• 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
• 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
• 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.
Bonus-5points
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
• 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
• 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
• 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?
• 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
• iron.
• oxygen.
• silicon.
• magnesium.
A lithium ion is much less reactive than a lithium atom because it
• is much more massive.
• has a full outermost energy level.
• has a negative electric charge.
• is in a different group in the periodic table.