Qualitative Analysis
Description that doesn't use numbers
Quantitative Analysis
Descriptive form that does use #'s
Precision
the closeness of a set of measurements of the same quantity made in the same way
Accuracy
the closeness of measurements to the correct or accepted value of the quantity measured
Length
meter (m)
Volume
V
Temp
Kelvin (K)
Time
second (s)
Mass
kilogram (kg)
Density
(g/cm3), (kg/l)
Volume
The amount of space an object takes up
Mass
the amount of matter in an object
Density
How compact something is
Matter
Anything that has mass and takes up space
Weight
the force of gravity on an object
physical property
can be observed without changing the identity of the substance (mp,bp,fp,density)
physical changes
Doesn't change what substance is (tear paper, break glass, change form, solid-liquid-gas)
chemical property
Ability to undergo change (rust, corrode, burn, decompose)
chemical changes
changes into a new substance (burns, reacts, decomposes, rusts
homogenous mixture (solution)
same consistency through out
heterogenous mixture
different consistency throughout
Element
A pure substance made of only one kind of atom
Compound
substance made of atoms of 2 or more different elements joined by chemical bonds
Law of Conservation of Mass
Mass is not created or destroyed, only transformed.
Dalton(Atomic Theory)
Elements are composed of extremely small particles called atoms.- All atoms of a given element are identical (same size, mass, and properties)- Atoms of 1 element are different from others-Atoms can physically mix or chemically combine only in whole number ratios
Rutherford
Gold foil experiment, discovered nucleus
JJ Thompson:
discovered the electron, plum pudding model
Mendelev
Proposed 1st periodic table where elements were arranged according to Atomic Mass
Atomic #
# of protons, # of electrons (not in ion)
Atomic mass
Number of protons and neutrons
Mass #
protons + neutrons
Isotope (deuterium, tritium):
Element with different electron number (2,3)
Valence Electrons
electrons in the outermost shell
S, P, D, F.
2, 6, 10, 14
Aufbau Principle
E-'s fill orbitals from the lowest Energy level 1st
Pauli exclusion
suborbital hold at most 2 electrons with opposite spin
Hund's Rule
when e-'s occupy orbitals of equal energy, one electron enters each orbital until all the orbitals contain one electron with equal spin
Ionic bond
Formed when one or more electrons are transferred from one atom to another
Oxidation #'s
possible charges an atom of an element can have
Covalent bond
A chemical bond formed when two atoms share electrons
Octet Rule
gain or lose electrons to get a full outer shell of 8
Lone pair
a pair of electrons that is not involved in bonding
VSEPR theory
repulsion b/w valence e-'s causes them to move as far away from each other as possible
polyatomic ion
A charged group of covalently bonded atoms. (define and know them)
Polar Bond
a covalent bond in which electrons are shared unequally
Nonpolar bond
a covalent bond in which electrons are shared equally
van der Waals forces
the two weakest intermolecular attractions- dispersion interactions and dipole forces
dispersion forces
the weakest of all molecular interactions, are caused by the motion of electrons
hydrogen bonds
When a H is bonded to a very electronegative atom
dipole interactions
occur when polar molecules are attracted to one another
chemical equation
A short, easy way to show a chemical reaction, using symbols.
Reactants
A starting material in a chemical reaction (left side)
Products
Ending materials in a chemical reaction (right side)
s
solid state
liquid
liquid state
g
gas state
aq
aqueous, water
arrows
yields, produces
catalyst
substance that speeds up the rate of a chemical reaction
Avogadro's number
6.02 x 10^23 (atoms to 1 number)
S04 -2
Sulfate
CO3 2-
Carbonate
ClO3 -1
Chlorate
NO3 -1
Nitrate
PO4 -3
Phosphate
C2H3O2 -1
Acetate
OH -1
Hydroxide
NH4 +1
Ammonium