Unit 3.1 Test Review--Covalent Bonds
Prefixes are used in naming...
Covalent compounds
Tetrahedral (Shape)
VSEPR shape for four bonding regions
Linear (Shape)
VSEPR shape for only two atoms, or no lone pairs off the central atom.
Trigonal Planar (Shape)
VSEPR shape for three bonding regions with no lone pairs off the central atom
Trigonal Pyramidal (Shape)
VSEPR shape for three bonding regions with one lone pair off the central atom
Bent - (Shape)
VSEPR shape for two bonding regions with one or two lone pairs off the central atom
triple covalent bond
a bond formed by sharing three pairs of electrons
double covalent bond
a bond that involves two shared pairs of electrons
molecular compound
a compound composed of molecules, nonmetals
lone pair
a pair of valence elecctrons that is not shared between atoms
nonmetals are
anions
covalent bond
atoms held together by sharing electrons
special rule for prefixes
be careful with an i and o when element begins with a vowel you might have to drop the last letter
most polyatomic cations and anions contain
both covalent and coordinate covalent bonds compounds containing polyatoic ions include both ionic and covalent bonding
metals are
cations
covalent compounds names to formulas
easy, write it as you see it no criss cross
Octet rule in covalent bonding
in covalent bonds electron sharing usually occurs so that atoms attain 8 electrons (2 for Hydrogen)
know types of compounds
ionic- metal and nonmetal covalent-nonmetals and both must contain a pai for example a metal and a pai
covalent and molecular
mean the same thing (nonmetals) so elements share
Prefixes are:
mono-1 di-2 tri-3 tetra-4 penta-5 hexa-6 hepta-7 octa-8 nona-9 deca-10
molecule
neutral group of atoms joined together by covalent bonds
electron dot structures
represents the shared pair of electrons of the covalent bond by 2 dots or a dash for example H-H
Single covalent bond (simple def)
shares only one pair of electrons
the negative charge of a polyatomic ion
show the number of electrons as well as the number of valence electrons of the atoms present
the VSEPR theory enables the prediction of a 3 dimensional molecular shape because the valence electron pairs
stay as far apart as possible
molecular formula
the chemical formula of a chemical compound shows how many atoms of each element a molecule contains DOESNT TELL YOU ABOUT A MOLECULES STRUCTURE
VSEPR Theory
the repulsion between electron pairs causes molecular shapes to adjust so that the valence electron pairs stay as far away as possible
the electron dot structure for a neutral molecule contains
the same number of electrons as the total number of valence electrons in the combining atoms
polyatomic ion
tightly bound group of atoms that has a positive or negative charge and behaves as a unit
Single covalent bond
two atoms held together by one pair of electrons.sharing a pair of electrons are joined by this. for example hydrogen gas consists of diatomic molecules whose atoms share only one pair of electrons forming a single covalent bond
Rules for naming covalent compounds
use prefix chart if the first element doesnt have a number then name it as you see it remember no ide for first element for example it would be carbon if first element does have a number then choose the correct prefix (dont add ide to ending) for the second element choose the correct prefix and change the ending to ide also be careful bc of vowel rule
VSEPR
valence shell electron pair repulsion theory
hydrogen is only one that
wont have 8 (octet)
