the study of matter and the changes that it undergoes
New cards
5
chlorofluorocarbon
Man-made chemicals containing chlorine, fluorine, and carbon
New cards
6
conclusion
a judgment based on the information obtained
New cards
7
control
a standard for comparison
New cards
8
hypothesis
A tentative explanation for what has been observed
New cards
9
mass
the amount of matter an object contains
New cards
10
matter
anything that has mass and takes up space.
New cards
11
model
a visual, verbal or mathematical explanation of data collected from many experiments
New cards
12
observation
the act of gathering information
New cards
13
ozone
Three particles of oxygen located in the stratosphere that protect the earth from harmful ultraviolet radiation
New cards
14
qualitative data
information that describes physical characteristics.
New cards
15
quantitative data
numerical information
New cards
16
scientific method
n organized process used by scientists to do research that provides a method for them to verify the work of others
New cards
17
technology
The practical use of scientific information. (ex: nuclear power, artificial limbs)
New cards
18
theory
an explanation that has been supported by many, many experiments.
New cards
19
accuracy
How close a measurement is to an accepted value (or actual value)
New cards
20
base unit
a defined unit based on an object or event in the physical world
New cards
21
conversion factor
a ratio of equivalent values used to express the same quantity in different units
New cards
22
derived unit
a unit that is a combination of base units
New cards
23
dimensional analysis
A method of problem-solving that focuses on the units used to describe matter
New cards
24
graph
a visual representation of information (line, bar, circle)
New cards
25
Kelvin
the base unit for temperature
New cards
26
precision
How close a series of measurements are to one another
New cards
27
second
the base unit for time
New cards
28
significant figure
all the known digits plus one estimated digit
New cards
29
chromatography
based on the tendency of one substance to travel across the surface of a material
New cards
30
compound
a combination of two or more different elements that are combined chemically
New cards
31
chrystallization
making a pure solid drop out of a solution
New cards
32
distillation
based on differences in boiling points
New cards
33
element
cannot be separated into simpler substances
New cards
34
extensive properties
dependent upon the amount of substance present
New cards
35
filtration
a technique that uses a porous barrier to separate a solid from a liquid
New cards
36
heterogeneous mixture
a mixture that does not blend smoothly throughout and the individual substances remain distinct
New cards
37
mixture
a combination of two or more pure substances in which each pure substance retains its individual chemical properties
New cards
38
percent by mass
The ratio of the mass of an element to the total mass of the compound
New cards
39
homogeneous mixture
a mixture that has a constant composition throughout; it always has a single phase
New cards
40
law of conservation of mass
Mass is neither created nor destroyed during a chemical reaction - it is conserved
New cards
41
solid
definite shape & volume, particles vibrate in place, tightly backed together
New cards
42
law of definite proportions
Regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
New cards
43
solution
a uniform mixture that may contain solids, liquids, or gases (also called a homogenous mixture)
New cards
44
law of multiple proportions
When different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other elements in a ratio of small whole numbers
New cards
45
states of matter
the physical forms in which all matter on earth naturally exists (solid, liquid & gas)
New cards
46
liquid
constant volume, take the shape on of the container, particles flow past one another, evenly spaced particles
New cards
47
substance
matter that has a uniform and unchanging composition
New cards
48
vapor
gaseous state of a substance that is a liquid or solid at room temperature
New cards
49
alpha particle
4 protons and 2 neutrons (identical to a Helium nucleus).
New cards
50
alpha radiation
nuclear reaction involving the release of an alpha particle. It is deflected toward a negative source when released between two electrically charged plates
New cards
51
atom
the smallest particle of an element that retains the properties of the element
New cards
52
atomic mass
the weighted average mass of the isotopes of that element
New cards
53
atomic mass unit
the unit used to describe the mass of atoms. It is equal to 1/12 the mass of a carbon-12 atom
New cards
54
beta particle
a high speed electron with a -1 charge released during beta decay
New cards
55
beta radiation
radiation that is made of beta particles. It is deflected toward a positive source when released between two electrically charged plates
New cards
56
nucleus
A tiny, dense positively charged region at the center of the atom
New cards
57
proton
subatomic particle with a mass of 1 amu and charge of +1 located in the atom's nucleus
New cards
58
radiation
rays and particles emitted by the radioactive materials
New cards
59
radioactivity
a process whereby substances spontaneously emit radiation
New cards
60
cathode ray
a negative stream of particles
New cards
61
nuclear equation
a type of equation that shows the atomic number and the mass number of the particles involved,
New cards
62
nuclear reaction
reactions that involve a change in an atom's nucleus.
New cards
63
Dalton's atomic theory
theory that marked the beginning of early atomic theory
New cards
64
electron
negatively charged particles (no mass, charge -1)
New cards
65
gamma ray
high energy radiation that has no electrical charge and no mass, usually accompanies other radioactive particles and accounts for most of the energy lost during decay
New cards
66
isotope
atoms with the same number of protons but a different number of neutrons.
New cards
67
mass number
\# protons + # neutrons
New cards
68
neutron
subatomic particle with a mass of 1 amu and charge of 0 located in the atom's nucleus
New cards
69
atomic emission spectrum
set of frequencies of the electromagnetic spectrum emitted by atoms of the element
New cards
70
amplitude
wave's height from origin to crest or origin to trough
New cards
71
atomic orbital
the three-dimensional region around an atom's nucleus that describes the electron's probable location
New cards
72
aufbau principle
states that each electron occupies the lowest energy orbital available
New cards
73
de Broglie equation
lambda = h / mv
New cards
74
electromagnetic radiation
form of energy that exhibits wavelike behavior as it travels through space
New cards
75
electromagnetic spectrum
includes all fors of electromagnetic radiation, with the only differences being the frequency and wavelengths
New cards
76
electron configuration
the arrangement of electrons in an atom
New cards
77
electron dot structure
electron symbol (represents the atomic nucleus and inner-level electrons) surrounded by dots representing valence electrons
New cards
78
energy sublevel
the energy levels contained within a principle energy level
New cards
79
frequency
number of waves that pass a given point per second
New cards
80
ground state
lowest allowable energy state
New cards
81
Heisenberg uncertainty principle
it is impossible to know the precise velocity and position of a particle (electron) at the same time
New cards
82
Hund's rule
states that when equal energy orbitals are available, electrons will enter one at a time. When all orbitals are half-filled, pairing will occur
New cards
83
Pauli exclusion principle
a maximum of 2 electrons can occupy a single atomic orbital
New cards
84
photoelectric effect
the phenomenon in which photoelectrons are emitted from a metal's surface when light of a certain frequency shines on the surface
New cards
85
photon
the particle of electromagnetic radiation with no mass that carries a quantum of energy
New cards
86
principle energy level
the major energy levels of an atom
New cards
87
principle quantum number
n, which the quantum mechanical model assigns to indicate the relative sizes and energies of atomic orbitals
New cards
88
quantum
minimum amount of energy that can be gained or lost by an atom
New cards
89
quantum mechanical model of the atom
an atomic model in which electrons are treated as waves; also called the wave mechanical model of the atom
New cards
90
wavelength
shortest distance between equivalence points on a continuous wave
New cards
91
electronegativity
the relative ability of and atom to attract electrons in a chemical bond.
New cards
92
halogen
group 7A elements
New cards
93
group
the vertical columns in the periodic table.
New cards
94
alkaline earth metal
group 2A elements (reactive elements)
New cards
95
ionization energy
the energy required to remove an electron from a gaseous atom.
New cards
96
ion
atom is bonded group of atoms with a positive or negative charge
New cards
97
metalloid
Elements with physical and chemical properties of both metals and nonmetals (used as semi-conductors)
New cards
98
noble gas
group 8A elements (extremely unreactive elements)
New cards
99
octet rule
atoms tend to gain, lose, or share electrons in order to acquire a full set of eight valence electrons. This gives them a noble gas configuration.
New cards
100
periodic law
the periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number
Studied by 2 people
Note 
Flashcard (20)