Chem 142 - Midterm 2 Flashcards
ionic bond
atoms held together by electrostatic forces resulting from electrons that are transferred from one atom to another
covalent bond
atoms held together by the sharing of electrons
metallic bond
“sea of electrons” freely distributed among atoms
polar covalent bonds
atoms held together by an unequal sharing of electrons
non polar covalent bonds
atoms held together by an equal sharing of electrons
dipole moment
quantitative measure of bond polarity
formal charge
the charges assigned to an atom assuring all the electrons in its bonds are shared equally
radical
an atom that has a single (or odd number) valence e instead of a lone pair
hypervalent
an atom that has more than 8 electrons
resonance
a lewis dot structure with the same connectivity but different distributions of electrons
steric number
the number of “things” attached to a central atom
electron domain geometry
the arrangement of all electron groups around a central atom, regardless of what kind of groups they are
molecular geometry
the arrangement of all bonding electron groups around a central atom, accounting for the affect of the lone pairs
ionic compounds
formed from bonds between metals and nonmetals
covalent compound
formed bonds between non metals
polyatomic ions
molecular compounds which have gained or lost electrons in order to become stable
stock system
convention of naming ions using the element name followed by the charge listed in parentheses
mole
the number of atoms a sample needs for its mass in g to equal its mass in amu
molar mass
the mass of one mole of a substance
synthetic reaction
a+b=c
decomposition reaction
c=a+b
single replacement
a+b=c to c+b=a
stoichiometry
the ratio between the amount of each species reacted and produced
empirical formula
the smallest ratio of atoms in a molecule
molecular formula
the number of atom of each element in a molecule
limiting reactant
a reactant that runs our before the others
excess reactant
left over after the reaction
