Matter
anything occupying space and having mass
Simplest Form of Matter
debatable
Atom
neutrons + protons + electrons [ nucleus ]
Element
collection of atoms (same type)
different atoms have different types of atoms
Example of an Element
anything on the periodic table
Compound
combine two or more different elements by forming chemical bonds
have constant composition
Example of a Compound
H2O
Mixture
combination of two or more elements or compounds
Homogeneous Mixture
combination is the same throughout
called solutions, not visibly distinguishable parts
Example of Homogeneous Mixture
air
Heterogeneous Mixture
composition is not uniform
has visibly distinguishable parts
separate mixtures by physical change
Example of Heterogeneous Mixture
trail mix
Physical Change
doesn't change formula of compounds/elements; usually changes the state (gas⇆liquid⇆solid)
Example of Physical Change
melting
Chemical Change
Separating (breakdown) compounds into elements by making or breaking chemical bonds
Example of Chemical Change
burning
Hypothesis
Possible explanation for an observation
Test hypothesis through experiment
Theory
Set of hypothesis that explains some natural phenomenon
often called models
explains why
Law
one statement summarizing what happens
can be a mathematical equation
Example of a law
Ideal Gas Law
PV=nRT
Qualitative Observation
general observations not requiring a number
Example of qualitative data
Colors, textures, smells, tastes, appearance, beauty, reactivity, state, etc.
Quantitative Observation
observation requiring a number and unit
a measurement
example of quantitative observation
How long, heavy, etc
Scientific Method
observations, hypothesis, experiment, theory
exa
10^18 (E)
peta
10^15 (P)
tera
10^12 (T)
giga
10^9 (G)
mega
10^6 (M)
kilo
10^3 (k)
hecto
10^2 (h)
deka
10^1 (da)
deci
10^-1 (d)
centi
10^-2 (c)
mili
10^-3 (m)
micro
10^-6 (miu)
nano
10^-9 (n)
pico
10^-12 (p)
femto
10^-15 (f)
atto
10^-18 (a)
uncertainty
all measurements have uncertainty
assume +/- 1 in last digit
precision
closeness of a measurement to each other
reproducibility
accuracy
closeness of a measurement to accepter, or true value
SigFig rules for counting
nonzero integers and captive zeros - significant
zeros on left - not significant
zeros on right - significant only if theres a decimal
exact numbers - infinite significant figures
SigFig rules for addition/subtraction
same number of decimal places as number with fewest
SigFig rules for multiplication & division
number with fewest SigFigs limits SigFigs in answer
SigFigs when using constants
don't allow them to limit amount of SigFigs
Dimensional Analysis Set Up
(original unit A/1)(unit B/unit A)(unit C/unit B)
% error
abs(true result-experimental)/true result x 100
related to accuracy
Dalton's Atomic Theory
each element is made up of atoms
Atoms of the same element are alike, atoms of different elements are different
Compounds are formed when atoms of 2 or more elements combine. (a given compound always have the same composition)
Law of Conservation of Mass: during chemical reaction, atoms are rearranged, not created or destroyed
Atomic Structure: JJ Thomson
cathose ray rube experiments
beam deflected by magnet (particles are charged)
current moves a paddlewheel (particles have mass)
Conclusion: a negatively charged particle is one of the fundamental particles of the atom
Atomic Structure: Rutherford
gold foil and alpha particle experiment
most went straight through (atom mostly empty space)
some were deflected slightly (protons in nucleus (+) repel the alpha particles (+))
a few bounced back (very dense nucleus)
nuclues makes up the _, electons make up the _
mass; volume
electrons
negative charge 9.10939 x 10^-31 kg
protons
positive charge 1.67265 x 10^-27 kg
neutrons
no charge 1.67495 x 10^-27 kg
Structure of the atom
mostly empty space
tiny nucleus surrounded by orbiting electrons
nucleus contains most of mass (n+p)
Atomic Number (Z)
number of protons (unique) number of electrons (when neutral)
Mass Number (A)
Number of protons + neutrons
Isotopes
Atoms of the same element that have different numbers of neutrons
Cations
electrons are lost (metals)
Roman numeral indicates charge
Anions
electrons are gained (nonmetals)
root of element name + ide suffix
Periodic Table
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Ionic Bonds
cations/anions simplest= metal + nonmetal metal in a compound gaining or lossing electrons
Covalent Bonds
nonmetal + nonmetal sharing electrons
H2O
water (neutral)
NH3
Ammonia (neutral)
C6H12O6
glucose (neutral)
HClO4
perchloric acid (neutral)
Hg2
Mercury (I) 2+
NH4+
Ammonium +1
NO2
Nitrite -1
NO3
Nitrate -1
SO3
Sulfite -2
SO4
Sulfate -2
HSO4
hydrogen sulfate (bisulfate) -1
OH
Hydroxide -1
CN
Cyanide -1
PO4
Phosphate -3
HPO4
Hydrogen Phosphate -2
H2PO4
dihydrogen phosphate -1
NCS or SCN
Thiocyanate -1
CO3
Carbonate -2
HCO3
hydrogen carbonate (bicarbonate) -1
ClO or OCl
Hypochlorite -1
ClO2
Chlorite -1
ClO3
Chlorate -1
ClO4
Perchlorate -1
C2H3O2
Acetate -1
MnO4
Permanganate -1
Cr2O7
Dichromate -2
CrO4
Chromate -2
O2
Peroxide -2
C2O4
Oxalate -2
S2O3 2-
Thiosulfate -2
HF
hydrofluoric acid
HCl
hydrochloric acid
HBr
hydrobromic acid
HI
hydroiodic acid