Chapter 2 vocab Flashcards
What did dalton do
bring back the idea of the atom. created “Daltons Atomic Theory” based on 3 laws
what are the 3 laws dalton based his theory on
law of constant composition
law of conservation of mass
law of multiple proportions
what does the law of constant composition mean
that there is the same number of atoms in any sample. every grain of salt is NaCl. discovered by joseph proust
what does the law of conservation of mass mean
the total mass of substances present at the end of a chemical process is the same as the mass in the beginning
what is the law of multiple proportions
if i make a new compound I can only add or subract by a whole atom, not half at atom
4 postulates of daltoms atomic theory
- each element is composed of small particles called atoms
- all atoms of a given element are identical, but the atoms of one element can differ from t he atoms of other elements
- atoms of one eleemtn cant be changed into atoms of a diff eleement by chemical reactions, elements cant be created or destroyed
- compounds are formed when atoms of more than one element combine
who tested the electon? and what?
JJ thomson used cathode rays to discover charge to mass ratio of 1.76E^8 coulombs/gram
millikan disovered charge and mass of an electron (the oil drop)
what is radioactivity
spontaneous emission of high radiation by an atom
who studied radioactivity
marie and pierre curie. and henri becquerel observed it
what did radioactivity prove
led to a discovery that an atom had subatomic particles and energy
Three types of radiation?
a` positive
a ^ negative
a~ no charge
how was the nucleas discovred
shot positive particles at a thin sheet of gold foil to observe the pattern of the particles
What is most of an atom?
empty space
what is in a nucleus
protons and neutrons
Proton mass
1.0073 amu
Nuetron mass
1.0087 amu
Electron mass
close to 0 (5.486E^-4 amu)
What is an atomic number
the number of protons in the nucleus
top left of an element symbol resembles what
the mass number
bottom left of an element symbol resemles what
the atomic number
how to get mass #
protons AND neutrons
how to get atomic #
protons OR electrons
What does isotope mean
atoms of the same element with different masses, meaning different # of neutrons
Amu means?
Atomic mass unit
1 amu =
1.66054 E^-24 g
Atomic weight =
(equation)
sum of ( (isotope mass) x ( fractional natural abundance) )
Periodic table row?
periods
periodic table column ?
groups
Metals ?
on left
elements in same what have similar chemical properties?
groups/ columns
nonmetals?
on right
metalloids ?
diagonal middle line
1A is
alkali metals
2A is
Alkaline earth metals
6A is
Chalogens
7A is
Halogens
8A is
Noble gases
Periodicity def
repeating pattern of properties and reactivity
metals traits
shiny
left side (besides H)
conduct heat and electricity
solids (besides Mercury)
Non metals traits
right side (and H)
solid, liquid or gas at room temp
metalloids traits
sometimes like metal, sometimes like nonmetals
steplike line
Chemical formula ? for water
H2O
Molecular compounds ?
with molecules. almost always contain only nonmetals
Diatomic molecules. name the 7
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Bromine
Iodnine
2 types of formulas
empirical or molecular
Empirical formula def
gives the lowest whole number ration of atoms of each element in a compound
molecular formulas def
give the exact number of atoms of each element in a compound
can you go from empirical to molecular?
no
structural formulas
they show the order in which atoms are attached. not 3 D
what can be used to show a 3d model of atoms
perspective drawings, ball and stick models, and space filing models
Positively charged ion
cation
negatively charged ion
anion
Ions def
when an atom of a group of atoms loses or gains electrons, it becomes an ion
Cation means what about the atom
it lost at least one electron, Monatomic are formed by metals
ANion means what about the atom
it gained at least one electron, monatomic are formed by nonmetals, execpt the noble gases
Octel rule ?
Atoms try to reach a number equal with group 8A . the nobel gases
Monoatomic vs Polyatomic ions
Poly means a group of atoms
what is NH4 +
a polyatomic cation
what is SO4 2-
a polyatomic anion
Ionic compund def
generally formed between metal snad nonmetals. electrongs go from metal to nonmetal. only writen in empirical formulas.
Mg +2 paired with N -3
Mg3N2
Inorganic Nomenclature writing means a polyatomic cation will end in what ?
write name as is if regular cation
ium for polyatomic
Inorganic Nomenclature writing means a anion will end in what ? what about a polyatomic anion?
ide for regular anion
write name as is if polyatomic
(NH4)2SO4
Ammonium Sulfate
FeCl
Iron (II) Chloride
NaCl
Sodium Chloride
Fe3(PO4)2
Iron (II) Phosphate
