Chapter 2 Flashcards
Molecules
With similar atoms
Compounds
with different atoms
Atomic Number
Top left, # of protons (and electrons)
Atomic mass
Number under symbol, #N + #P
Isotopes
of neutrons change but protons stay, mass # changes, found naturally
Different forms of same element
Valence electrons
electrons in outer shell, atoms want full shells -> unreactive
octet rule
Ionic bonds
unequal sharing of electrons, donating or gaining
Covalent bonds
Mostly sharing of electrons
Cation
Ionic bond, positively charged, donates electron
Anion
Ionic bond, negatively charged, receives electron
Nonpolar
mostly equal sharing
Polar
Slightly unequal sharing, one atom attracts stronger and creates dipole moment (makes partial + and -)
Ionic compounds
Solid/Crystal : strong
Weak in water
Intramolecular
Within molecules
Intermolecular
Between molecules
Electronegativity
Polar covalent bonds, partial neg and pos, one atom attracts e more
Increases L to R, Decreases Top to Bottom
Hydrogen bonds
Weak bonds between molecules, strength in number of bonds, high electronegativity
Van der Waals
Spontaneous weak bonds, between multiple molecules, all atoms have+/-
Atoms become polarized and temporarily attracted
weaker than covalent/ionic
Chemical rxns
Make and break chemical bonds, move electrons around, all theoretically bidirectional
Water
essential for life, 75% planet water, polar covalent bonds
Unique properties of water
Cohesion and Adhesion, high specific heat, evaporative cooling, universal solvent (like dissolves like)
Cohesion
Attraction between molecules of the same substance
Adhesion
Attraction between molecules of different substances
Ionization of water
2 “h bonded” H2o
H3O+
HO-
