Gabi Zweig
November 1, 2010
SCIENCE REVIEW SHEET
Safety Rules
 Anything that sounds logical
Scientific Method
 Hypothesis- a possible explanation that can be tested by
experimenting.
 Theory-explains a wide range of observations.
 (SI-the units that scientists use all around the world.)
 There are 2 different kinds of experiments that
you can do: Controlled Experiment and Observed
Experiment.
 In an observed experiment you are just
watching what is happening.
 In a controlled experiment you are doing
something specifically so that the experiment will go
a certain way.
 In a Controlled Experiment there is a
dependent variable, and independent variable and a
control group.
 Independent variable-the thing that you are
testing and is supposed to change results. It is the
single factor that the scientist changes.
 Dependent variable-the thing that gets effected by the independent
variable
 Control group-the thing that stays the same; nothing changes.
 There are always problems in science and experiments whether
something is ethical or not. It’s the standard of comparison in an
experiment.
Graphs
We use different types of graphs to chart different types of information.
Especially in science, graphs are very important.
The 3 major types of graphs that we use are:
 Bar Graph
 Line Graph
 Pie Chart
Properties of Life
1. Cellular Organization
2. Homeostasis-the maintenance of stable internal conditions in spite of
changes in the external environment
3. Metabolism-the sum of all the chemical reactions carried out in an
organism.
4. Responsiveness-living organisms respond to their external
environment.
5. Reproduction-the process by which organisms make more of their
own kind from one generation to the next.
6. Growth
7. Heredity-when an organism reproduces, it passes on its own traits to
its offspring in a process
Diseases
 Epidemiology-the study of how diseases spread.
 Genome- the complete set of genetic information for an organism.
 Ways to prevent the spread of disease:
1. Vaccination-a medical procedure that allows a person to resist
infection by a disease.
2. Quarantine-being isolated
3. Antibiotics-medicine that you can take to get better.
Assistive Technology:
Artificial prosthetics (limbs)
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4.
Battlefield Medicine:
Blood clotting
Bandaging
Remote Surgery
Robot Surgery
 Genetic Engineering- a technology in which the genetic material of a
living cell is changed.
An example of Genetic Engineering:
If DNA were modified to kill of the pest so there would be less pest eating
our food.
Biological Research
 Biotechnology-the application of knowledge of biology to improve
the lives of humans.
 Biomimetics-the kind of technology that produced Velcro. It’s the
application of biological processes and systems to solve design and
engineering problems. Mimicking and imitating things.
Ex: sap, submarines (fish), airplane (birds), parachute (squirrel),
jungle gym (spider web), tree house (birds’ nest)
 Biometrics-things to determine someone’s identity.
Ex: fingerprints, iris scan, DNA, retnal (part of your eye) scan, teeth
 Imaging System
CAT SCAN-x-rays-3D ... this kind of scan is better for the bones
MRI- magnetic resonance. This can be used for seeing everything. They are
more expensive.
Atoms
 Atom- the smallest unit of matter that can’t be broken down by
chemical means
 Atoms are made out of 3 things: protons, neutrons, and electrons
 Protons-positive charge
 Neutron-no charge
 Electron-negative charge
 Element-a substance made up of atoms that have the same # of
protons
 Isotopes-atoms that have a different number of neutrons
 There are (more than) 3 levels in the electron cloud.
 The first level can hold 2 electrons, the second level can hold 8 and
the third level can also hold 8
 Valence electrons-electrons in the outer most shell
 Compound-a substance made of the bonded atoms of two or more
different elements
 There are 3 different kinds of bonds: covalent, ionic, hydrogen
 Covalent bond-a way that atoms bond is by sharing valence electrons
 Ionic bond-the attractive force between oppositely charge ions
 Hydrogen bond-attracts the negative pole of other nearby molecules.
When it is bonded to an oxygen, nitrogen, or fluorine atom, hydrogen
atoms have a partial charge nearly as great as a proton’s charge
 Atomic #-the # of protons and electrons
 Atomic Mass- the # of protons and neutrons.
 Ion- an atom or group of atoms that has an electric charge because it
has gained or lost electrons.
 Polar-it has positive and negative ends. There are some charges on
each end.
 Non-polar-there are no charges
 Solution-a mixture in which 2 substances are uniformly distributed
 Solute-substance that dissolves in solution
 Solvent-substance in which solute is dissolved
 Suspension-a mixture of water and small non-dissolved non-polar
molecules.
EX: Water is polar therefore non-polar molecules do not dissolve in water,
but polar and ionic do dissolve in water.
Na+ (sodium) is an example of a positive ion.
Cl- (chlorine) is an example of a negative ion.
NaCl (sodium-chloride) is an example of an ionic compound.
O2 (oxygen) is an example of a (non-polar) molecule.
H2O (water) is an example of a polar (or compound) molecule.
Properties of Water
 Ice floats- water becomes less dense as a solid than as a liquid because
when water freezes, hydrogen bonds lock water molecules into a
crystal structure that has empty spaces.
 Water absorbs and retains heat
 Water molecules stick to each other
 Water molecules stick to other polar substances
Cohesion-the attraction of particles of the same substance
Adhesion-the attraction of particles of different substances
Solutions
Solution- a mixture in which ions or molecules of one or more substances
are evenly distributed in another substance.
Acids-compounds that form extra hydronium ions when dissolved in water.
Bases-compounds that form extra hydroxide ions when dissolved in water.
pH Scale
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Numbers from 1-7 are acidic.
Numbers from 8-14 are basic.
Number 7 is neutral.
The lower the number is on the acidic level, the more acidic it is.
The higher the number on the basic level, the more basic it is.
To neutralize an acid you would add a base and to neutralize a base
you would add an acid.