Lecture 2_190607 Flashcards
Matter
1) atoms
2) ions
3) elements
4) compounds
Atoms
protons + charge, 1 amu (1.0073 amu)
neutrons 0 charge, 1 amu (1.0087 amu)
electrons – charge, 0 amu (0.00055 amu)
*almost all space is occupied by electron clouds
Ions
cations (ca+ions) “+”
anions “-“
Elements
only one kind of atom
Compounds
molecules (molecular compounds)
ionic compound
Physical properties
intrinsic (independent of amount of material)
i.e. color, density, etc.
extrinsic
i.e. mass, volume, etc.
Chemical properties
reactivity
Atomic number
of protons
Atomic mass
of protons + # of neutrons
For isotopes
= Average atomic mass (Cl is 75.7%35+24.3%37 = 35.4)
35Cl has 17 protons and 18 neutrons and an atomic mass of ~35
37Cl has 17 protons and 20 neutrons and an atomic mass of ~37
Neutral atoms
of protons = # of electrons
Covalent bonds
strong bonds between non-metals (plastics, H2O)
*both atoms in the bond contribute one valence electron in order to form a shared pair
Noncovalent
Ionic interactions = Interaction of charged atoms (Na, K, Mg, Ca, ions)
Hydrogen bonds = Attraction of Hδ+ to Oδ- & Nδ- (H bound to O, N)
Hydrophobic interactions = H2O repulsion of non-polar atoms (C-C, C-H, “oil & water”)
Hydrophillic interactions = polar (ETOH & H2O)
Van der Waals forces = Very weak
Naming molecular compounds
1) name each element
2) indicate how many (mono, di, tri, etc.)
3) add –ide to the last element
N2O
Dinitrogen monoxide (nitrous oxide)
NO
Nitrogen monoxide (nitric oxide)
S Cl2
Sulfur dichloride
P2O5
Diphosphorous pentoxide
C Cl4
Carbon tetrachloride
SiO2
Silicon dioxide
H2O
Dihydrogen oxide (water)
Na+
Sodium ion
K+
Potassium ion
Ca^2+
Calcium ion
Cl-
Chloride ion
S^2-
Sulfide ion
P^3-
Phosphide ion
Cu+
Copper(I)
Cu^2+
Copper(II)
Fe^2+
Iron(II)
Fe^3+
Iron(III)
NH4+
Ammonium ion
H3O+
Hydronium ion
HCO3-
Bicarbonate ion
HSO4-
Bisulfate
OH-
Hydroxide ion
C2H3O2-
Acetate ion
CN-
Cyanide ion
H2PO4-
Dihydrogenphosphate ion
SO4^-2
Sulfate ion
Formulas of ionic compounds
1) Charges must equal 0
2) ionic compounds
NaCl Sodium chloride
K2SO4 Potassium sulfate
NaHCO3 Sodium bicarbonate
FeSO4 Iron(II) sulfate
Fe2(SO4)3 Iron(III) sulfate
Mole and Molar Mass
A mole is X grams of a substance, where X is its molar mass. A mole will contain 6.022x10^23 molecules.
A molar (M) solution contains 1 mole of a substance in 1 liter of solution. mM = 10-3 M (millimolar) μM = 10-6 M (micromolar) nM = 10-9 M (nanomolar) pM = 10-12 M (picomolar)
Molar Mass (MM) is the sum of the atomic weights of the atoms to make up a compound. NaCl = (Na, MM = 23.0) + (Cl, MM = 35.5) → 58.5 g/mole
Periodic Table Groups
Columns - Electrons in outer shell
Periodic Table Periods
Rows = Protons / Molar Mass
Valence electron
outer shell electron that can participate in the formation of a chemical bond