Studied by 17 people
chemistry
the study of matter and the changes that matter undergoes
matter
is anything that has mass and occupies space
hypothesis
is a tentative explanation for a set of observations
law
is a concise statement of a relationship between phenomena that is always the same under the same conditions
theory
is a unifying principle that explains a body of facts and/or these laws that are based on them
scientific method
A series of steps followed to solve problems
Step 1 of Scientific Method
observation
Step 2 of Scientific Method
Identify the problem
Step 3 of Scientific Method
Research the problem
Step 4 of the Scientific Method
develop a hypothesis
Step 5 of Scientific Method
Design an experiment
Step 6 of Scientific Method
Collect and analyze data
Step 7 of Scientific Method
Draw conclusions
states of matter
solid, liquid, gas
Compound
a substance composed of atoms of two or more elements chemically united in fixed proportions
Mixture
A combination of two or more substances in which the substances retain their distinct identities
homogeneous mixture (solution)
a mixture in which the composition is uniform, hard separate
heterogeneous mixture
a mixture in which the composition varies, easy to separate
Element
a substance that cannot be separated into simpler substances by chemical means
2 substances
elements and compounds
seperating heterogenous mixtures
filtration
Seperating Homogeneous Mixtures
distillation
Crystallization
separates mixtures based on differences in solubility
Tera (T)
10^12
Giga (G)
10^9
Mega (M)
10^6
Kilo (k)
10^3
Deci (d)
10^-1
Centi (c)
10^-2
Milli (m)
10^-3
Micro (weird u)
10^-6
Nano (n)
10^-9
Pico (p)
10^-12
Celsius to Kelvin
Celsius + 273
Celsius to Fahrenheit
C=5/9(F-32)
kelvin
known as the absolute temp. scale, lowest possible temp 0K
density
mass/volume
mass
density x volume
volume
mass/density or length x width x height
physical change
state of matter changes but not the identity
example of physical change
liquid H20 vs. solid H2O
chemical change
A change in matter that produces one or more new substances
example of chemical change
water H20 to peroxide H2O2
Rule 1 of Sig Figs
All non-zero digits are significant
Rule 2 of Sig Figs
captive zeros are significant
Rule 3 of Sig Figs
trailing zeros after or before an significant number
Rule 4 of Sig Figs
leading zeros are NOT significant
Rule 5 of Sig Figs
trailing zeros before an implied decimal are ambiguous and are avoided by using scientific notation
Sig Fig Multiplication/Division
the answer has the same number of sig figs as the factor with the smallest number of sig figs
Sig Fig Addition/Subtraction
the number of sig figs in the answer is determined by the number of places after the decimal in the problem
extensive properties
a property that depends on the amount of matter in a sample
intensive properties
a property of matter that depends only on the type of matter in a sample and not on the amount
extensive properties examples
mass and volume
intensive properties example
density, boiling pt, freezing pt
unit convertion
a multi-step process that involves multiplication or division by a numerical factor, selection of the correct number of significant digits, and rounding
SI units (International System of Units)
standards fixed by international agreement in the International System of Units
What are SI units?
kg, m, s, A, K, mol, cd
accuracy
tells us how close a measurement is to the true value
precision
tells us how close multiple measurements of the same thing are to one another
Dalton
proposed the atomic theory / atom
Thomson
discovered the electron and charge to mass ratio
Thomson's experiment
Cathode Ray Tube
Rutherford
discovered the nucleus and protons
Rutherford's experiment
Gold foil experiment
Chadwick
Discovered the neutron
Bohr
electrons circular orbit around nucleus
Millican
determined charge of electron
Millican's Experiment
oil drop experiment
current model
electrons occupy regions of space around nucleus
Atomic Theory
all atoms of a given element are identical, having the same size, mass, and chemical properties (false: isotopes). One element is different from the atoms of another element
chemical reaction
rearranges atoms, doesnt create or destroy them
Proust's Law of Definite Proportions
didn't realize that elements can combine in different ratios (CO vs CO2)
Electron charge
-1
Law of Multiple Proportions (Dalton)
realized that elements can combine in different ratios
electron mass
9.10938 x 10^-28 g
proton charge
+1
proton and neutron mass
1.67493 x 10^-24
neutron charge
0
isotopes
atoms with different number of neutrons
atomic number
number of protons
columns (horizontal)
groups or families
rows (vertical)
periods
elements in pairs
H2, N2, O2, F2, Cl2, Br2, I2
atomic mass unit (amu)
a mass exactly equal to one-twelfth the mass of one carbon-12 atom
1 amu
1/12 the mass of a carbon-12 atom
find isotope mass or natural abundance
elements amu = (given amu 1)(natural abundance given 1) + (given amu 2)(natural abundance 2)
atomic weight
Average of the mass numbers of all isotopes
mass number
the sum of the number of neutrons and protons in an atomic nucleus
ion
An atom or group of atoms that has a positive or negative charge.
cation
ion with a positive charge
anion
ion with a negative charge
how to become cation
if neutral atom LOSES one or more electrons
how to become anion
if neutral atom GAINS one or more electrons
monatomic ion
contains only one atom
polyatomic ion
contains more than one atom
oxoanions
are polyatomic anions that contain one or more oxygen atoms and one atom of another element
hydrates
are compounds that have a specific number of water molecules attached to them
acids
molecular compounds that release hydrogen ions when dissolved in water
naming binary acids
hydro + base name of nonmetal + -ic + acid
naming oxyacids
ate - ic, ite - ous + acid
Note 
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