Dalton's Postulates
elements are composed of atoms
all atoms of a specific element are identical (but different from atoms of other elements)
Atoms of one element cannot be exchanged with atoms of another
atoms cannot be created/destroyed
compounds are combinations of atoms of one or more elements
every sample of a compound have the same relative numbers of each kind of atom in it
Law of Conservation of Mass
Total mass of substance present at end of chemical process is same as before the process happened
Law of multiple proportions
when two elements combine to form more than one compound, the mass of one element, which combines with a fixed mass of the other element, will always be ratios of whole numbers.
Who discovered electrons and with what
J.J. Thomas with Cathode Rays
define radioactivity
what did it's discovery lead to
Spontanous emission of high-energy radiation by an atom
the discovery of the proton and the nucleus
Who discovered the Nucleus
Ernest Rutherford Shot alpha particles through gold sheet, some were deflected, they were bouncing off of nucleouses
the "nuclear model"
Masses of the three subatomic particles
the mass of protons and nucleuses are virtually the same
the mass of elections is so small it is negligible
Element symbols
How to calculate mass number
what are isotopes
Atoms of the same element with different masses
aka different number of neutrons but same number of protons as the basic atom
J.J. Thomson made the plum-pudding atom model
charges of protons and electrons
protons: +1
Electrons: -1
Atomic Mass Unit
amu
a base unit of measurement for the mass of atoms. It is purely for simplification
atomic number
number of protons
mass number
number of protons + neutrons
number of protons = number of electrions
No net charge
ratio of oxygen vs hydrogen in water in mass
8 times as much oxygen as hydrogen
how do most elements occur naturally
mixtures of isotopes
define atomic weight
the average atomic mass of an elements isotopes
atomic mass equation
what info is given on a square on the periodic table
Atomic number, Atomic symbol, Atomic weight
periods vs groups
periods = horizontal columns
groups = vertical rows
elements within groups tend to be...why?
similar
they have the same number of valence electrons
metallic elements everything except the right
metaloids
the elements that make up the "divide" between metals and nonmetals on the periodic table. They have physical characteristics from both sides
define molecule
two or more of the same element bound together
diatomic molecule
molecules that consist of two atoms
oxygen vs Ozone
O2 - essential to life, odorless
O3 - toxic, pungent smell
molecular compounds
made of atoms of different elements
How does most matter appear in nature.
they are composed of molecules or ions
all but the noble gasses which appear as isolated atoms
molecular formula vs empirical formula
molecular = exact numbers of each element in a molecule (Benzene: C6H6)
emperical = the ratio of each element to the others (in Benzene, for every Carbon atom there is one Hydrogen atom, CH)
structural formula
Shows the most information
Shows how all the atoms are connected
Ball-and-stick model
balls = atoms
sticks = bonds
space-filling model
Good for showing relative size of the atoms but angle is harder to see
Perspective drawing chemistry
cations vs anions
After chemical process has occurred if elections are added or taken from an atom that atoms becomes an ion and gains a charge
cation - positive charge
anion - negative charge
how is net charge shown
superscript ( 1+ , 2- , + , -, etc. )
In general do metals tend to gain or loose electrons
In general do non-metals tend to gain or loose electrons
metals lose
non-metals gain
polyatomic ions
Ions of many atoms
ions behave very differently from their parent atoms
why do elements tend to gain/loose elections to get to the same number of elections as the closest noble gas
the number of elections that the noble gases have are very stable. (also why noble gases form few compounds)
ionic compound
(different from molecular compound because molecules and ions are different things)
a compound made up of cations and anions
Opposite charges attract so cations and anions often combine to create a net 0 charge and a compound
difference between ionic compounds and polyatomic ions????
????
Are metals usually cations or anions
Are non-metals usually cations or anions
what does this tell us
metals are cations
non-metals are anions
SO, ionic compounds are generally combinations of metals and nonmetals
molecules are generally combinations of nonmetals only
most Ionic compounds can only be written with which formula? why?
empirical
most ionic compounds can have different numbers of atoms. They just have to have the same ratios of elements
element symbol
number of protons or electrons
How to find the number of neutrons from the mass number and atomic number
subtract the atomic number from the mass number because mass number is neutrons + protons and atomic number is just protons
finding atomic weight
sum of the masses of all that element's isotopes multiplied by the fractional natural abundance
Possible test/quiz question
find what is blank (the boxes)
The periodic table is arranged by...
Dr. Frampton uses which group labeling method?
color coding
atomic number (number of protons or electrons)
IA,IIA, etc.
black = solid at room temp
Red = gas at room temp
properties of metals
metals - shiney, solid at room temp, good conductors, malleable, ductile, will form cations
properties of nonmetals
brittle, solid/liquid/or gas at room temp, not shiny, not conductive, will form anions
properties of metalloids
sometimes act like metals and sometimes act like Nonmetals
What are the Group A elements called
What are the Group B elements called
A = main group elements (or representative elements)
B = transitions elements (transition metals)
List of diatomic elements
H2 I2 N2 Cl2 Br2 O2 F2
HINClBrOF "hincklebrof"
define chemical nomenclature
system used in naming substances
organic vs inorganic compounds
organic = contains carbon and/or hydrogen
inorganic = doesn't
oxyanions derived by adding H+
Hydrate PDF in blackboard
Zinc and gold have only one charge?
kill me please
Hydro carbon (organic chemistry)
a molecule that only contains hydrogen and carbon
Methane (organic chemistry)
CH4
Propane (organic chemistry)
C3H8
alcohols are...their names end in..
organic compounds...-ol
