C165
Atom
basic building block of matter.
contains: proton, neutron (in the center or nucleus of the atom) and electrons (around the outside of the
atom)
The mass of the atom is from the weight of the protons and neutrons. Electrons have no weight
Proton
A subatomic particle that has a positive charge and that is found in the nucleus of an atom
* if you add or take away more protons to and element- it changes what it is
Neutron
A subatomic particle that has no charge and that is found in the nucleus of an atom
Electron
A subatomic particle that has a negative charge and is on the outside rings or shells of the atom
valence electrons
Electrons on the outermost shell or ring of an atom
* the part of the atom that is involved in chemical reactions
*Because this electron is far from the nucleus, it can interact with other atoms more easily than the inner
electrons.
Element
A pure substance made of only one kind of atom
consist entirely of only 1 type of atom.
only 92 elements
atomic number
the number of protons in an atom
For neutral atoms of a given element the atomic number also gives the total number of electrons found
within the electron clouds.
Compound
A substance made up of atoms of two or more different elements joined by chemical bonds
,chemical bond
the force that holds two atoms together
Molecule
two or more atoms held together by covalent bonds
type of a compound
ex: water H2O
A molecule can consist of more than two atoms.
A molecule forms when electrons are shared in a covalent bond.
Not all molecules are compounds.
The number of kinds of molecules can change when they undergo a chemical reaction. Molecules do not
always stay the same like atoms!
organic compounds
compounds that contain carbon and hydrogen
scientific law
a concise statement that summarizes the results of many observations and experiments
*tells us what will occur based on based on research with large amounts of data collected over a long
period of time
*about very specific behaviors in nature
scientific theory
a well-tested concept that explains a wide range of observations
*cannot be fully proved true with enough testing
*Can be about many different phenomena
Big Bang Theory
The theory that the universe originated in a huge explosion that released all matter and energy.
13.8 million years ago
began as a tiny region of space and expanded
formation of six specific kinds of simple nuclei of the elements hydrogen, helium, and lithium
Stars and galaxies formed from the hydrogen and other light nuclei being pulled together by gravity.
,Plate Tectonic Theory
theory that Earth's lithosphere is divided into tectonic plates
these tectonic plates move slowly on top of the asthenosphere
Atomic theory
a theory that states that all matter is composed of tiny particles called atoms.
dependent variable
The outcome factor; the variable that may change in response to manipulations of the independent
variable.
the variable that you measure as the result of varying the independent variable.
independent variable
The experimental factor that is manipulated; the variable whose effect is being studied.
the variable that the experimenter changes to change the dependent variable
the one you change directly, to cause a change in the dependent variable.
Scientific Measurement
a standard or fixed quantity used by everyone when measuring.
Today, scientists worldwide use the Systeme International d'Unites, or SI, system of measurement. This
measurement system is also used for everyday measurements in many countries.
time: seconds: s - clock or stopwatch
mass: kilogram: kg -triple beam or electric balance
length: meter: m - ruler
temp: kelvin: K - or c* - thermometer
electricity: amperes
light: candela
substance: moles
mega
M- 1,000,000
kilo
k- 1,000
deci
d- 0.1 one tenths 10^-1
centi
c- 0.01 one hundredth 10^-2
milli
m- 0.001 one thousandth 10^-3
micro
μ- 0.000001 10^-6
nano
n 0.000000001 billionth 10^-9
Speed
meter per second m/s
, area
square meter m2
Volume
cubic meter m3
l x w x h= meter x meter x meter= m^3
Density
kilograms per cubic meter kg/m3
Derived units
Combinations of units or combinations of fundamental quantities
When the base quantities are combined
ex:
speed- m/s
area- m^2
volume- m^3
density- kg/m^3
Liquid Displacement
Process for finding the volume of an irregular solid
the volume of an irregularly shaped object needs to be determined by a different method. If an object is
placed in a liquid, it will displace the liquid. The volume of the liquid the object displaces is equal to the
volume of the object.
measure volume without object first
put object in cylinder
measure volume with object in it
subtract the new volume from the old volume
direct relationship
a relationship in which one variable increases with an increase in another variable
A relationship between two variables exists when an increase of one variable results in an increase of the
other, or a decrease of one results in a decrease of the other.
For example, assuming you maintain a constant speed, the distance your car travels is directly related to
the time of travel.
distance traveled by car and the amount of gas used- both increase
amount of people at a birthday party and the amount of cake eaten- both increase
inverse relationship
a relationship in which one variable decreases when another variable increases