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Final Exam Study Guide
The Nature of Science
1. Scientific Method includes:
Read and research the topic to learn as much about it as possible.
State the problem (what question are you trying to answer?)
Form a hypothesis (an educated guess)
Test the hypothesis includes
experiment
make observations
record data
analyze data
come to a conclusion
communicate results with others
2. During an experiment, all the factors that can change during an experiment are called
the variables. An experiment in which all variables except one remain the same is a
controlled experiment. A control is a standard for comparison in an experiment.
3. The unit for length (distance) in the metric system is the meter.
The unit for mass is the gram. The unit for volume is the liter.
The prefix kilo means 1000X, the prefix milli means 1/1000th.
4. A theory is a unifying explanation for a broad range of hypotheses and observations
that have been supported by testing.
5. Mass is how much matter an object contains. Volume is the amount of space an
object occupies.
Matter and its Changes
1. The four states of matter are solid, liquid, gas and plasma.
2.
Names and symbols of common elements.
nitrogen, N gold, Au
lead, Pb helium, He iron, Fe sodium, Na
calcium, Ca hydrogen, H sulfur, S oxygen, O carbon, C mercury, Hg
copper, Cu silver, Ag silicon, Si
3. The atomic number of an atom is the number of protons in the atom. The atomic mass
of an atom is the protons + the neutrons in an atom. If you know the mass and the atomic
number, you can solve for the number of neutrons by subtracting the atomic number from
the atomic mass.
4. Atoms are made of subatomic particles called protons, neutrons, electrons.
Protons are in the nucleus and have a positive charge. Neutrons are in the nucleus and
do not have a charge. Electrons are in the energy levels outside the nucleus and have
a negative charge. Protons & neutrons are about the same size, while electrons are
about 1/2000th the size of either protons or neutrons.
5. Definitions:
atom- the smallest particle of an element
ion- an atom that has lost or gained an electron, it is either positive or negative.
isotope- a form of an element with the same atomic number, but a different
atomic mass. They differ by the number of neutrons the atom has. All elements
have isotopes. Example: carbon-12 and carbon-14 are isotopes.
compound- 2 or more elements, chemically combined in a definite proportion by
mass. Example: NaCl sodium chloride.
mixture- 2 or more substances mixed together in any proportion. Can be separated
by ordinary physical means like filtering. Ex- soil and water.
condensation-the change from the gaseous to the liquid state of matter.
evaporation- the change from the liquid state to the gaseous state of matter.
melting-the change from the solid to the liquid state of matter.
freezing-the change in state from a liquid to a solid.
6. Atoms form compounds by gaining or losing electrons. If an atom loses an electron, it
becomes a positive ion. If an atom gains electrons, it becomes a negative ion. The ions
are held together because of opposite charges.
7. A change in matter that produces new substances is a chemical change. A change in
matter that does not produce new substances is a physical change. Example: grinding
chalk into a powder is a physical change.
8. A chemical property tells you what you can expect an element to do. Metals give
electrons to form positive ions. Nonmetals gain electrons to form negative ions.
A physical property describes a substance. Example-metals have luster, are malleable,
and ductile, and are good conductors of heat & electricity.
9. Density is found by dividing the mass by the volume of an object. The volume of
objects with an irregular shape can be found by displacement of water.
10. Elements are composed of atoms.
11. In the molecule CO2, there is 1 carbon atom and 2 oxygen atoms. The subscript is
the number of atoms of that element. Total=3. In the molecule H2O, there are 2
hydrogens and 1 oxygen for a total of 3.
Minerals
1. Definitions
streak- the color of the powder of a mineral when rubbed against unglazed
porcelain plate.
hardness-Mohs scale includes 10 minerals from talc to diamond. Hardness means
that the mineral can scratch another mineral.
luster- shine. Reflects light from its surface.
cleavage- if a mineral splits evenly along a flat surface. It depends on how the
atoms are arranged in the crystal of the element.
inorganic-does not come from a living organism. Usually means it does not
contain carbon.
diamond-a form of carbon that has been under intense heat and pressure. The
hardest mineral on Mohs’ scale.
2. There are more than 3000 known minerals. 100 of them are common, 20 of them
make up the rocks in the Earth’s crust.
3. A mineral is a naturally occurring, inorganic solid that has a crystalline structure and a
definite chemical composition.
4. The element iron comes from the mineral hematite or the mineral magnetite.
5. Gemstones, metals, quartz, talc, fluorite, calcite, kaolin, gypsum, corundum are
examples of minerals.
6. Titanium is a light weight, strong metal that is used in paints, in alloys for artificial
bone and joint replacements and in aircraft construction.