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