regents concepts and skills Flashcards
1
Q
matter is classified as
A
a pure substance or as a mixture of substances
2
Q
three phases of matter
A
solid, liquid, gas
structure shows phase
3
Q
a pure substance
A
has a constant composition and constant properties
4
Q
elements cannot be
A
broken down by chemical change
5
Q
mixtures can be
A
separated by physical means
6
Q
when different substances are mixed
A
a homogenous or heterogeneous mixture is formed
7
Q
proportions of a mixture can be varied, but
A
each component retains its original properties
8
Q
different properties of substances…
A
permit physical separation of the components
9
Q
forms of energy
A
chemical, electrical, electromagnetic, thermal, mechanical, nuclear
10
Q
physical change results in
A
rearrangement of existing particles in a substance with the same properties
11
Q
chemical change results in
A
formation of different substances with changed properties
12
Q
the modern model of the atom
A
has evolved over a long period of time through the work of many scientists
13
Q
each atom has a
A
nucleus with an overall positive charge surrounded by one or more negatively charged electrons
14
Q
subatomic particles in the nucleus are
A
neutrons (n) and protons (+)
15
Q
proton
A
positive
16
Q
neutron
A
neutral
17
Q
electron
A
negative
18
Q
number of protons equals
A
number of electrons in an atom
19
Q
protons and neutrons are
A
about equal in mass
20
Q
electrons are (mass)
A
smaller than protons/neutrons
21
Q
isotopes
A
same number of protons, but different number of neutrons
22
Q
atomic number
A
number of protons
identifies element
23
Q
mass number
A
sum of protons and neutrons
identifies an isotope
24
Q
when an atom gains electrons
A
it becomes negative
25
when an atom loses electrons
it becomes positive
26
chemical compound can be represented by
a specific chemical formula and assigned name based on the IUPAC system
27
types of chemical formulas
empirical
molecular
structural
28
in all chemical reactions there is a conservation of
mass, energy, and charge
29
types of reactions include
synthesis, decomposition, single-replacement, double-replacement
30
the mass of each proton and each neutron
is appx. equal to one amu (atomic mass unit)
31
mass of an atom is very nearly qual to
its mass number
32
the average atomic mass of an element is
the weighted average of the masses of naturally occurring isotopes
33
empirical formula is
the simplest whole number ratio of atoms in an element
34
empirical formula is different from
the molecular formula (actual ratio of atoms in a molecule of that compound)
35
formula mass of a substance
sum of the atomic masses of it's atoms
36
molar mass (gram formula mass)
the mass of one mole of that substance
37
one mole
avogadro's number
| 6.02 x 10^23
38
percent composition by mass of each element in a compound
can be calculated mathematically
39
a balanced chemical equation represents
conservation of atoms
40
coefficients in a balanced chem equation can be used to determine
mole ratios in reaction
41
heat is a transfer of energy from
a body of higher temp to a body of lower temp
42
thermal energy is associated with
the random motion of atoms and molecules
43
chemical and physical reactions can be
exothermic or endothermic
44
energy released or absorbed is equal to
the difference between potential energy of products and potential energy of reactants
45
energy released or absorbed by a chemical reaction can be represented by
a potential energy diagram
46
entropy
a measure of randomness or disorder of a system
47
greater entropy
greater disorder
48
systems in nature tend to undergo changes toward
lower energy, higher entropy
49
temperature is the measurement of
average kinetic energy of the particles in a gas
50
temperature is not
a form of energy
51
the concept of an ideal gas
a model to explain the behavior of gases
52
a real gas is most like an ideal gas when
the real gas is at low pressure and high temperature
53
kinetic molecular theory (KMT) for an ideal gas is that the particles are/have
in random, constant straight-line motion
separated by great distances relative to size
no attractive forces between them
collisions that may result in the transfer of energy between particles (but total energy of system remains the same)
54
kinetic molar theory describes
relationships of pressure, volume, temperature, velocity, and frequency
55
equal volumes of different gases at the same temp and pressure contain
equal numbers of particles
56
concepts of kinetic and potential energy can be used to explain
processes such as fusion (melting), solidification (freezing), vaporization (boiling, evaporation), condensation, sublimation, deposition
57
stability of an isotope
ratio of neutrons and protons in nucleus
58
most nuclei are stable, but
some are unstable and decay spontaneously, editing radiation
59
each radioactive isotope has
a specific mode and rate of decay
60
transmutation
a change in the nucleus of an atom that converts the atom to another
61
transmutation can occur
naturally or can be induced by bombarding the nucleus with high-energy particles
62
spontaneous decay can involve the release of
alpha particles
beta particles
positrons
gamma radiation
63
different emissions differ in
mass, charge, ionizing power, penetrating power
64
nuclear reactions include
natural transmutation
artificial transmutation
fission
fusion
65
both benefits and risks are associated with
fission and fusion reactions
66
nuclear reaction can be represented by equations that include
symbols that represent atomic nuclei
subatomic particles
emissions such as alpha, beta, gamma
67
the energy released in a nuclear reaction (fission or fusion) comes from
the fractional amount of mass converted into energy
68
the energy released during nuclear reaction is much greater than
the energy released during chemical reactions
69
risks with the use of radioactive isotopes
biological exposure
longterm storage and disposal
mutations
nuclear accidents
70
benefits of radioactive isotopes (in research, medicine, and industry)
```
radioactive dating
tracing chemical/biological processes
industrial measurements
nuclear power
detection and treatment of disease (such as cancer)
```
71
each electron in an atom has its own
distinct amount of energy
72
when an electron gains a specific amount of energy it is in the
excited state
73
electron going from higher to lower energy state
energy is emitted (can identify the element)
74
electron orbitals
ground state
| most probable electron location
75
valence electrons
the outer most electrons
76
valence electrons affect
chemical properties of the element
77
lewis dot structure
shows valence electrons
78
placement on periodic table
indicate physical and chemical properties
79
elements on table are arranged in
increasing atomic number
80
elements can be classified by their properties, such as
metals, nonmetals, metalloids (B, Si, Ge, As, Sb), noble gases
81
elements can be differentiated by physical properties, such as
density, conductivity, malleability, solubility, and hardness
82
elements can be differentiated by heir chemical properties by
how they act in a chemical reaction
83
groups 1, 2, and 13-18
each group has same # of valence electrons
| have similar properties, but not helium
84
as the elements go down in groups
atomic radius increases
electronegativity decreases
first ionization energy decreases
metallic properties decrease
85
when atom gains 1+ electrons
radius increases
| becomes more negative
86
when an atom loses 1+ electrons
radius decreases
| becomes more positive
87
degree of polarity is determined by
electronegativity difference between two bonded atoms
88
when a bond is broken
energy is absorbed
89
when a bond is formed
energy is released
90
atoms attain a stable valence electron configuration by
bonding with another atom
91
noble gases have
stable valence electron configurations and generally do not bond
92
major categories of compounds
ionic
| molecular
93
chemical bonds are formed when valence electrons
transfer from one atom to another (ionic)
share between atoms (covalent)
mobile within a metal (metallic)
94
electronegativity indicates
how strongly an atom attracts electrons in a chemical bond
95
electronegativity values are assigned
according to arbitrary scales
96
metals tend to react with
nonmetals to form ionic
97
nonmetals tend to react with
other nonmetals to form molecular (covalent) compounds
98
ionic compounds containing polyatomic ions have
both ionic and covalent bonding
99
intermolecular forces created by an unequal distribution of charge result in
varying degrees of attraction between molecules
100
the polarity of a molecule is determined by the
shape of the molecule and the distribution of charge around
101
symmetrical molecules
nonpolar
102
asymmetrical molecules
polar
103
diatomics
H, N, F, O, I, Cl, Br
104
hydrogen bonding is
a strong intermolecular force
105
organic compounds contain
carbon atoms that bond to one another
106
how to name compounds
IUPAC
107
hydrocarbons
hydrogen and carbon only
108
saturated hydrocarbons
only single carbon-carbon bonds
109
unsaturated hydrocarbons
at least one multiple carbon-carbon bond
110
categories of organic compounds
```
organic acid
alcohol
esters
aldehydes
ketones
ethers
halides
amines
amides
amino acid
```
111
types of organic reactions
```
addition
substitution
polymerization
esterification
fermentation
saponification
combustion
```
112
isomers of organic acids
have the same molecular formula, but different structures and properties
113
a solution is a
homogenous mixture
114
solubility is dependent on
temperature, pressure, chemical natures of solute and solvent
115
concentration can be expressed as
molarity
percent by mass
parts per million
116
salt
freezing point decreases
| boiling point increases
117
greater concentration
the greater the effect
118
electrolyte
releases mobile ions in aq solution
| allows solution to conduct electricity
119
rate of chemical reaction depends on
```
temp
concentration
nature of reactants
surface area
presence of a catalyst
```
120
Le Châtelier's principle is used to
predict effects of stress on a system at equilibrium
121
catalyst provides
alternative reaction pathway that has lower activation energy
122
collision theory
a reaction is most likely to occur if reactants of particles collide w/ proper energy and orientation
123
some chemical and physical changes can reach
equilibrium
124
at equilibrium the rate of forward reaction equals
the rate of reverse reaction
125
the measurable quantities at equilibrium
remain constant
126
acidity or alkalinity are measured by
pH level
127
on the pH scale, each decrease of one unit of pH represents
a tenfold increase in hydronium ion concentration
128
in the process of neutralization, an arrhenius base and an arrhenius aside react to form
salt and water
129
arrhenius bases yield
hydroxide ions as the only negative ions in an aq solution
130
arrhenius acids yield
hydrogen ions as the only positive ions in an aq solution
131
arrhenius bases and acids are
electrolytes
132
titration
lab process to determine concentration of an unknown
133
voltaic cells
spontaneously coverts chem. energy to elect. energy
134
electrolytic cells
require elec. energy to produce chem. change
| electrolysis
135
redox reaction involves
transfer of electrons
136
reduction
gain of electrons
137
half-reaction can be written
to represent reduction
| to represent oxidation
138
oxidation
loss of electrons
139
in a redox reaction
of electrons lost = # of electrons gained
140
oxidation states can be assigned to
atoms or ions
141
change in oxidation # indicates
that oxidation or reduction has occurred
142
an electrochemical cell can be
voltaic of electrolytic
143
in electrochemical cell
oxidation occurs at the anode
| reduction occurs at the cathode
