Ch 6 - Covalent Bonding Flashcards
what is covalent bonding?
attraction between the shared pair of negative electrons and the positive nuclei either side of it
when does covalent bonding occur?
occurs between two non-metals (groups 4,5,6,7)
occurs in solids, liquids and gases (at room temperature)
do covalent bonds conduct electricity and why
no
Electrons are shared to complete the outer shell
they can’t move therefore doesn’t conduct electricity
how are covalent bonds represented?
with dot and cross diagrams
usually only draw outside shells but unless this is specified it is safer to draw all the shells
what are the bonds between hydrogen atoms
very strong covalent bonds
what are hydrogen molecules
diatomic
(contains two molecules)
H2
what do molecules have?
a certain fixed number of particles
what is released when bonds are formed
energy
makes things involved more stable
the more bonds and atom can form, the more energy released, the more stable the bond becomes
what type of bond is formed in a hydrogen chloride molecule and what is its diagram
covalent bond
Chlorine has one unpaired electron on outer shell
Hydrogen has one unpaired electron on outer shell
Both atoms bond together and form a covalent bond
if hydrogen atom bonds with another hydrogen atom is it less or more stable
more stable
when hydrogen and chlorine bond together what molecule do they form
a hydrogen chloride molecule
what bond is formed in a chlorine molecule and what is its diagram
a covalent bond
each chlorine has an unpaired electron which is shared between the two chlorine atoms
what is the sybol and diagram for methane
symbol = CH4
the carbon atom has four unpaired electrons
they share one electron from four hydrogen atoms
what is they symbol and diagram for ammonia
the nitrogen atoms has three unpaired electrons
they share one electron from three hydrogen atoms
symbol = NH3
what is the symbol and diagram for water?
symbol = H2O
there are two unpaired electrons on the oxygen atom
they bond with two hydrogen atomssymbol = H2O
what is the significance of noble gas structures
ehen atoms bond covalently, they often produce outer electronic structures the same as noble gases
there are also lots of examples that look nothing like noble gas structures
what is the symbol and diagram for ethane?
symbol = C2H6
what is the symbol for a chlorine molecule
Cl2
what type of bond do each methane, ammonia and water form
covalent bonds
what type of covalent bonding is formed in carbon dioxide and what is its diagram
double
what type of covalent bonding in nitrogen and what is its diagram
triple
what is special about the structure of sodium hydroxide?
what is its diagram?
you have Na (a metal) and OH (a non-metal) - this makes it ionic
however, the O and H are both non-metals and that makes it covalent
what bonding is similar to that of methane and what is different?
ethane
there is a carbon-carbon bond also
how many electrons are shared by each atom in single covalent bonding?
one
how many electrons are shared by each atom in double covalent bonding?
two
how many electrons are shared by each atoms in triple covalent bonding?
three
does iodine crystal form a simple molecular structure or a giant covalent lattice?
what does its formation look like?
simple molecular