chemical bonding ionic bonds covalent bonds ionic bonding when an atom of a nonmetal takes one or...
TRANSCRIPT
CHEMICAL BONDING
• IONIC BONDS
• COVALENT BONDS
IONIC BONDING
When an atom of a nonmetaltakes one or more electrons
from an atom of a metalso both atoms end up with
eight valence electrons
IONIC BONDING
IS THE COMPOUND AN IONIC COMPOUND?
METALMETAL NONMETAL
SUBSCRIPTS
IONIC BOND FORMATION
Neutral atoms come near each other. Electron(s) are transferred from the Metal atom to the Non-metal atom. They stick together because of electrostatic forces, like magnets.
IONIC BONDING
Metals will tend to lose electrons and become
POSITIVE CATIONS
Normal sodium atom loses one electron to become sodium ion
IONIC BONDING
Nonmetals will tend to gain electrons and become
NEGATIVE ANIONS
Normal chlorine atom gains an electron to become a chloride ion
POLYATOMIC IONS--a group of atoms that act like one ion
NH4+1--ammonium ion
CO3-2--carbonate ion
PO4-3--phosphate ion
IONIC BONDING
IONIC BONDING
SODIUM SULFATE
Properties of Ionic Compounds
• Crystalline structure.
• A regular repeating arrangement of ions in the solid.
• Ions are strongly bonded.
• Structure is rigid.
• High melting points- because of strong forces between ions.
COVALENT BONDING
When an atom of one nonmetal
shares one or more electrons
with an atom of another
nonmetal so both atoms
end up witheight valence electrons
COVALENT BOND FORMATION
When one nonmetal shares one or more electrons with an atom of another nonmetal so both atoms end up with eight valence electrons
COVALENT BONDING
IS THE COMPOUND A COVALENT COMPOUND?
NONMETALNONMETAL NONMETAL
YES since it is made of only nonmetal elementsYES since it is made of only nonmetal elements
Covalent bonding
• Fluorine has seven valence electrons
F
Covalent bonding
• Fluorine has seven valence electrons
• A second atom also has seven
F F
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons
F F
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons
F F
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons
F F
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons
F F
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons
F F
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons Both end with full orbitals
F F
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons Both end with full orbitals
F F8 Valence electrons
Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons Both end with full orbitals
F F8 Valence electrons
Single Covalent Bond
• A sharing of two valence electrons.
• Only nonmetals and Hydrogen.
• Different from an ionic bond because they actually form molecules.
• Two specific atoms are joined.
• In an ionic solid you can’t tell which atom the electrons moved from or to.
Water
H
O
Each hydrogen has 1 valence electron
Each hydrogen wants 1 more
The oxygen has 6 valence electrons
The oxygen wants 2 more
They share to make each other happy
Water
• Put the pieces together• The first hydrogen is happy• The oxygen still wants one more
H O
Water
• The second hydrogen attaches
• Every atom has full energy levels
H OH
CovalentBonds
LET’SFIRSTREVIEWIONICBONDING
In an IONIC bond,electrons are lost or gained,resulting in the formation of IONS
in ionic compounds.
FK
FK
FK
FK
FK
FK
FK
FK+ _
FK+ _
The compound potassium fluorideconsists of potassium (K+) ions
and fluoride (F-) ions
FK+ _
The ionic bond is the attractionbetween the positive K+ ion
and the negative F- ion
Sowhatarecovalentbonds?
In covalent bonding,atoms still want to achievea noble gas configuration(the octet rule).
In covalent bonding,atoms still want to achievea noble gas configuration(the octet rule).
But rather than losing or gainingelectrons,atoms now share an electron pair.
In covalent bonding,atoms still want to achievea noble gas configuration(the octet rule).
But rather than losing or gainingelectrons,atoms now share an electron pair.
The shared electron pairis called a bonding pair
Cl2
Chlorineforms
acovalent
bondwithitself
ClClHowwilltwochlorineatomsreact?
ClClEach chlorine atom wants to gain one electron to achieve an octet
ClClNeither atom will give up an electron –chlorine is highly electronegative.
What’s the solution – what can theydo to achieve an octet?
ClCl
Cl Cl
Cl Cl
Cl Cl
Cl Cloctet
Cl Cl
circle the electrons foreach atom that completestheir octets
octet
Cl Cl
circle the electrons foreach atom that completestheir octets
The octet is achieved byeach atom sharing theelectron pair in the middle
Cl Cl
circle the electrons foreach atom that completestheir octets
The octet is achieved byeach atom sharing theelectron pair in the middle
Cl Cl
circle the electrons foreach atom that completestheir octets
This is the bonding pair
Cl Cl
circle the electrons foreach atom that completestheir octets
It is a single bonding pair
Cl Cl
circle the electrons foreach atom that completestheir octets
It is called a SINGLE BOND
Cl Cl
circle the electrons foreach atom that completestheir octets
Single bonds are abbreviatedwith a dash
Cl Cl
circle the electrons foreach atom that completestheir octets
This is the chlorine molecule,
Cl2
O2
Oxygen is also one of the diatomic molecules
How will two oxygen atoms bond?
OO
OOEach atom has two unpaired electrons
OO
OO
OO
OO
OO
OO
Oxygen atoms are highly electronegative.
So both atoms want to gain two electrons.
OO
Oxygen atoms are highly electronegative.
So both atoms want to gain two electrons.
OO
OO
OO
OO
OO
OOBoth electron pairs are shared.
6 valence electronsplus 2 shared electrons
= full octet
OO
6 valence electronsplus 2 shared electrons
= full octet
OO
two bonding pairs,
OOmaking a double bond
OO=For convenience, the double bond
can be shown as two dashes.
OO
OO=This is the oxygen molecule,
O2
this is so
cool!!
