Chapter 2 Flashcards
law of constant composition
compounds have definite composition; # of atoms in compound = always the same
law of conservation of mass
total mass of substances present at end of chemical process=same as mass of substances before
law of multiple proportions
if 2 elements combine to form a compound, the masses combined = ratio
dalton’s atomic theory (5 parts)
- matter = made of atoms
- atoms of 1 element = identical
- atoms of diff element= diff weights/properties
- atoms of diff elements combine to form compounds
- atoms aren’t created or destroyed
cathode rayes
(-) particle stream travels through (+) electrode; study electrons
Millikan oil-drop experiment
determined charge of electron = (-)
radioactivity
spontaneous emission of high-energy radiation
3 types of radiation
alpha, beta, gamma
alpha radiation
(+) charge; decay emission = 2 p + 2 n
beta radiation
(-) charge; decay emission = 1 e
gamma radiation
no charge; decay emission = gamma ray
“plum pudding model”
even spread of + charges through atom; radiation passes through center, rejected
nuclear atom (Rutherford, gold foil experiment)
most mass and (+) - dense nucleus; (-) moves in space around
subatomic particles
protons, neutrons, electrons; opposite charged attract, same repel
protons
1+
neutrons
neutral
electrons
1-
1 amu
1.66054 x 10^-24 g
atomic number
number of protons (=number of electrons)
mass number
protons + # neutrons
isotopes
atoms of same element
- (same atomic number- # proton = # electrons)
different masses (# of neutrons)
atomic weight
average atomic mass of element (using isotopes)
(isotope mass)x(fractional abundance)= atomic weight
mass spectrometer
determines atomic weights w/ accelerator
of protons =
of electrons
mass #
protons + neutrons
Alkali metals
1A: Li, Na, K, Rb, Cs, Fr
alkaline earth metals
2A: Be, Mg, Ca, Sr, Ba, Ra
Chalcogens
6A: O, S, Se, Te, Po
Halogens
7A: F, Cl, Br, I, At
noble gases
8A: He, Ne, Ar, Kr, Xe, Rn
metals
left side of table (from step line); shiny, conduct heat, solid (except mercury)
nonmetals
right of table (step line) + hydrogen
metalloids
elements that touch step line; properties of metals and nonmetals
diatomic molecule
molecule w/ 2 atoms
molecular compound
compound of molecules w/ 2+ atoms; always nonmetals
molecular formula
chemical formula w/ exact # of atoms in molecule (ex: H2O2)
empirical formula
simplest ratio
ion
charged particle; when atom loses/gains electrons
cation
(+), when electron is lost; metals
anion
(-), when electron is gained; nonmetals
cations: H+
hydrogen ion
cations: Na+
sodium ion
cations: K+
potassium ion
cations: Ag+
silver ion
cations: NH4+
ammonium ion
cations: Mg^2+
magnesium ion
cations: Ca^2+
calcium ion
cations: Zn^2+
zinc ion
cations: Cu^2+
copper(II)
cations: Fe^2+
iron(II)
cations: Pb^2+
lead(II)
cations: Al^3+
aluminum ion
cations: Fe^3+
iron(III)
polyatomic ion
group of atoms gain/lose electrons
ionic compounds
formed b/w metal and nonmetal (cation and anion)
metals are…
cations
nonmetals are…
anions
organic compound
contain carbon and hydrogen
acids: -ate –>
-ic acid
acids: -ite –>
-ous acid
acids: -ide –>
hydro- __ -ic acid
ex: chloride –> hydrochloric acid
binary molecules
2-element molecular compounds (nonmetal + nonmetal)
mono-
1
di-
2
tri-
3
tetra-
4
penta-
5
hexa-
6
hepta-
7
octa-
8
nona-
9
deca-
10
hydrocarbons
compounds w/ only carbon + hydrogen
alkanes
simplest class of hydrocarbons; each carbon = bonded to 4 other atoms
- name ends in -ane
- ex: CH4 = methane
isomers
molecules w/ same chemical formula, but diff structure
naming: polyatomic cation
add -ium ion
naming: anions
add -ide
naming: polyatomic anion
add -ide, -ate, -ite
oxyanions
anions w/ oxygen
naming: fewer oxygens
ends in -ite
