study guide Flashcards
(91 cards)
1
Q
Hypothesis
A
A testable explanation of a situation or phenomena
2
Q
Theory
A
An explanation of a natural phenomenon based on many observations and investigation over time.
3
Q
Scientific Law
A
a relationship in nature that is supported by many experiments.
4
Q
Science
A
is the use of evidence to construct testable explanations and prediction of natural phenomena, as well as, the knowledge generated through this process.
5
Q
Chemistry
A
The study of matter and the changes that it undergoes
6
Q
Pure research
A
Conducted to gain knowledge for the sake of knowledge itself.
7
Q
Applied research
A
Conducted to solve a specific problem
8
Q
Model
A
Is a visual, verbal, or mathematical explanationof experimental data
9
Q
Substance
A
(a.k.a. a chemical) is matter that has a definite and uniform composition.
10
Q
Mass
A
Is a measurement that reflecs that amount of matter.
11
Q
Weight
A
is a measure not only of the amount of matter but also of the effect of Earth’s gravitational pull on that matter
12
Q
Second
A
Time
13
Q
Meter
A
Length
14
Q
Kilogram
A
Mass
15
Q
Kelvin
A
The SI base unit for temperature is the kelvin (K)
16
Q
Derived unit
A
a unit that is defined by combination of base units (volume (cm^3) and density (g/cm^3)).
17
Q
Liter
A
volume
18
Q
Density
A
is a physical property of matter and is defined as the amount of mass per unit volume.
19
Q
Graph
A
is a visual display of data
20
Q
Significant figures
A
include all known digits plus one estimated digit
21
Q
Scientific notation
A
can be used to express any number as a number between 1 and 10 multiplied b 10 raised to a power.
22
Q
Dimensional factor
A
used to convert from one set of units to another
23
Q
Independent variable
A
is the variable that a scientist deliberately changes during an experiment.
24
Q
Dependent variable
A
variable whose value depends on, or changes in response to, the independent variable
25
Crystallization
is a seperation technique that results in the formation of pure solid particles of a substance from a solution containing the dissolved substance
26
Filtration
is a technique that uses a porous barrier to seperate a solid from a liquid
27
Sublimation
is the process during which a solid changes to vapor without melting, i.e., without going thorugh the liquid phase.
28
Crystal Lattice
is the arrangement of these atoms, or groups of atoms in a crystal
29
Lattice energy
is the energy required to break apart an ionic solid and convert its compnent atoms into gaseous ions
30
Formula unit
the simplest ratio of ions represented in an ionic compound
31
Distillation
is a physical separtion technique that is based on differences in the boiling points of the substance involved
32
Chromatography
is a technique that separates that components of a mixture dissolved in either a gas or a liquid based on the ability of each component to travel or to be drawn across the surface of a fixed substrate
33
Chemical change
a process that involves one or more substances changing into new substances
34
Physical change
a change such as this which alters a substance without changing its composition
35
Compound
made up of two or more diffent elements that are comined chemically in a fixed ratio
36
Mixture
is a combination of two or more pure substances in which each pure substance retains its indivdual chemical properties
37
Element
is a pure substance that cannot be separted into simpler substances by physical or chemical means
38
Solution
what homogeneous mixtures are referred to
39
Phase change
is a transition of matter from one state to another
40
Conservation of mass
states that mass is neither created nor destroyed during a chemical reaction--it's conserved
41
Vapor
refers to the gaseous state of a substance that is a solid or a liquid at room temperature.
42
Dalton's Atomic Theory
explains that the conservation of mass in chemical reactions is the result of the rearrangement of atoms during the reaction
43
Proton
positively charged ion
44
Neutron
is a subatomic particle that has a mass nearly equal to that of a proton, but carries no elecric charge.
45
Electron
negatively charged particles that are part of all forms of matter
46
Atomic mass
of an element is the weighted average mass of the isotopes of that element
47
Atomic number
the number of protons in an atom
48
Mass number
quantity of matter contained in an atom of an element.
49
Atomic mass unity
measure of atomic mass
50
Atom
is a particle of matter that uniquely defines a chemical element.
51
Nucleus
Atomic nuclei consist of electrically positive protons and electrically neutral neutrons.
52
Cathode ray
cathode ray, stream of electrons leaving the negative electrode (cathode) in a discharge tube containing a gas at low pressure,
53
Isotopes
An isotope is one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behavior but with different atomic masses and physical properties.
54
Heisenberg uncertainty principle
we cannot know both the position and speed of a particle, such as a photon or electron, with perfect accuracy
55
Electromagnetic radiation
Radiation that has both electric and magnetic fields and travels in waves.
56
Amplitude
is the displacement of a wave from zero.
57
Cation
positively charged ions
58
Anion
negatively charged ions
59
Ion
an atom or bonded group of atoms with a positive or negative charge
60
Chemical bond
Any rearrangement of electrons in two atoms that generates a force, causing the atoms to be bound to each other, forming a molecule.
61
Ionic bond
the electrostatic force that holds oppositely charged particles together in an ionic compound
62
Metallic bond
the force of attraction between these free-moving (delocalised) electrons and positive metal ions
63
Frequency
the number of waves that pass a certain point in a specified amount of time.
64
Wavelength
In a wave the distance between any given point and the same point in the next wave cycle.
65
Electromagnetic spectrum
complete range of all types of radiation that has both electric and magnetic fields and travels in waves.
66
Photon
tiny particle that comprises waves of electromagnetic radiation.
67
Ground state
the lowest energy state of an atom or other particle.
68
Quantum number
The set of numbers used to describe the position and energy of the electron in an atom
69
Atomic orbital
a mathematical term in atomic theory and quantum mechanics that describes the position and wavelike behaviour of an electron in an atom
70
Principal quantum number
describes the energy of an electron and the most probable distance of the electron from the nucleus
71
Electron configuration
the arrangement of electrons in orbitals around an atomic nucleus.
72
Valence
the property of an element that determines the number of other atoms with which an atom of the element can combine.
73
Electron dot diagram
diagrams in which the valence electrons of an atom are shown as dots distributed around the element's symbol.
74
Groups
a column in the periodic table of the chemical elements.
75
Period
The horizontal rows of the periodic table
76
Alkali metals
any of the six chemical elements that make up Group 1 (Ia) of the periodic table
77
Actinide series
atomic numbers 89-103
78
Transition elements
elements that have partially filled d orbitals.
79
Nonmetal
right side of the periodic table
80
Representative elements
elements from groups 1, 2, and 13-18 in the modern periodic table, possessing a wide range of chemical and physical properties
81
Halogen
a highly reactive groupd 17 element
82
Lanthanides series
in the periodic table, the f-block elements from period 6 that follow the element lanthanum
83
Noble gas
an extremely unreactive group 18 element
84
Metal
an element that is solid at room temp., a good conductor of heat and electricity, and generally is shiny; most metals are ductile and malleable.
85
Metalloid
an element that had physical and chemical properties of both metals and nonmetals
86
Inner Transition metal
a type of group B element that is contained in the f-block of the periodic table and is characterized by a filled outermost orbital, and filled or partially filled 4f and 5f orbitals.
87
Alkaline earth metals
groupd 2 elements in the modern periodic table and are highly reactive
88
Ionic
are compounds made up of ions that form charged particles when an atom (or group of atoms) gains or loses electrons.
89
Ionization energy
the energy required to remove an electronn from a gaseous atom; generally increases in moving from left-to-right across a period and decreases in moving down a group
90
Electronegativity
indicates the relative ability of an element's atoms to attract electrons in a chemical bond
91
Octet rule
states that atoms lose, gain, or share electrons in order to acquire the stable electron configuration of a noble gas
