A=P=E M-A=N
-Atomic number=Protons=Electrons -Mass Number-Atomic number=neutrons -mass number=atomic number+neutrons
in ion-electron equations, gain of electrons go on...
reaction side
in ion-electron equations, loss of electrons go on...
product side
Covalent molecular properties
-small molecules (discrete) -cannot conduct electricity-don't have any free particles which are free to move -fixed number of atoms -soluble(*like dissolves like) -low mp/bp -weak attractions between molecules
covalent network properties
-big -very strong -very high mp/bp (strong bonds must be broken) -insoluble -cannot conduct electricity(except graphite)-have to free electrons to carry charge -contain carbon(graphite, diamond), boron or silicone
structures
-tetrahedral -trigonal pyramidal -angular -linear
covalent bonds
-formed when two positive nuclei are held together by their common attraction for a shared pair of electrons -strong bond -non metals
ionic bond
force of attraction between the positive and negative ions (metals & non-metals)
properties of ionic compounds
-soluble in water + ionic substance -SOLIDS DON'T conduct electricity -liquid & molten conduct as ions are free to move
non-metal atoms will...
gain electrons to form negative ions
metal atoms will...
lose electrons to form positive ions
prefix rule
mon-1 di-2 tri-3 tetra-4 penta-5 hexa-6
Valency Rule
s-symbol v-valencies s-swap d-divide f-formula
single covalent bond
sharing 1 pair of outer electrons, H-H
double covalent bond
sharing 2 pairs of outer electrons, O=O
group ions
ions that contain more than type of atom
negative ions
-formed when non metal atoms gain electrons -atoms that gain electrons have more negative electrons than positive protons and so have a negative charge
positive ions
-formed when metal atoms lose electrons -atoms that lose electrons have more positive protons than negative electrons and so have a positive charge
ionic bond
-positive and negative ions are strongly attracted to each other, this is called electrostatic attraction -very strong bonds
ionic structure
-ionic compounds form a lattice structure of oppositely charged ions(held together by electrostatic forces) -all ionic compounds are solid at room temp. bc the ionic bonds in the lattice are very strong
ionic compound properties
-high mp/bp because strong bonds must be broken -dissolve in water and ionic solutions -solids DO NOT conduct -liquid/molten DO conduct as ions are free to move
when writing ionic formula
include charges