chemistry chapter 9.1

atoms in a compound are linked together by?

chemical bonds

attractive force between atoms that is strong enough to enable the group to act as a unit

chemical bond

crystalline solids with high melting MP and BP, conducts electricity well when molten, water sol, insol in nonpolar solvents

typical physical properties of ionic compunds

g,l,or s with low melting points, (L) state doesnt conduct electricity, insoluble in water,sol in nonpolar solvents

typical physical properties of molecular compounds

most important factor affecting how atoms form chem bonds

number of valence electrons in each atom involved

tend to react in a way that gives them a noble-gas electron configuration, like to have 8 valence electrons

atoms

principle that atoms tend to react in a way that gives them a noble-gas electron configuration

octet rule

what type of bonding tends to occur between two elements depends on their what?

their periodic properties

chemical bond that results from the sharing of valence electrons between atoms

covalent bond

hold atoms in a covelent bond together

the attraction of both +nuclei to the negatively charged electron cloud

two atoms sharing a a single pair of electrons

covalent bond/single bond

2-3 pairs of electrons shared by 2 atoms

multiple bond

sharing two pairs of electrons

double bond

3 pairs shared

triple bond

number of electron pairs shared in a bond

bond order

held together by covalent bonds, just as a neutral molecule is

polyatomic ion

a group of covalently bonded atoms that act as a single ion

polyatomic ion

formulas of covalent networks are

empirical formulas

hold atoms together in discrete molecules

covalent bonds

formation of a bond in which the electrons come from only one reactant

coordination

composed of billions or trillions of atoms that are bonded together into a single unit by strong covalent bonds

covalent networks

formula that shows a compound’s covalent bonds and nonbonding valence electrons

lewis structures

predicts how they will combine to form a covalent substance

lewis structure

electrons that circulate freely through the molecule instead of being bound to a single atom or pair of atoms

delocalized electron

bonding situation in which electrons are shared by more than two atoms

delocalization

often called resonance because a single, static drawing cannot accurately represent this spreading, chemists draw multiple "valid" Lewis structures (resonance contributors) and view the actual molecule as an average (the resonance hybrid) of all those structures combined

delocalization

drawn to indicate “resonance”

double headed arrow

covalent bond in which both atoms share electrons equally

nonpolar bond

can occur only in atoms with the same electronegativity

equal sharing of electrons

covalent bond in which electrons are shared unequally between atoms

polar bond

represented by δ (greek lowercase delta)

partial change

formed by bond or molecule that has a negative end and a positive end

dipole

typically means a 3d representation of a molecule that shows its shape and the position of its atoms

molecular model

two of the most common types of molecular models

ball and stick model and spacefilling model

represents each atom in a molecule as small sphere and represents covalent bonds as cylinders joining the spheres, shoes the atoms positions and the bonds between atoms, but it doesn’t show the atoms’ sizes or the size of the entire molecule

ball-and-stick model

shows the shape and approx. volume of the molecule, but the bonds and bond order are not explicity shown

spacefilling model