inorganic chemistry review. tightly packed; usually regular pattern vibrate, but generally don’t...

Inorganic Inorganic Chemistry Chemistry

ReviewReview

Tightly packed; usually Tightly packed; usually regular patternregular pattern

Vibrate, but generally don’t Vibrate, but generally don’t move from place to placemove from place to place

Close together; Close together; usually no regular usually no regular arrangementarrangement

Vibrate; move about; Vibrate; move about; slide past each otherslide past each other

Well separatedWell separated; no ; no regularregular arrangementarrangement

Vibrate and move freely at Vibrate and move freely at

high speeds.high speeds.

Composition of MatterComposition of Matter

MatterMatter - Everything in - Everything in universe is composed of universe is composed of mattermatter• Matter is anything that Matter is anything that

occupies space or has occupies space or has massmass

MassMass – quantity of – quantity of matter an object hasmatter an object has

WeightWeight – pull of – pull of gravity on an objectgravity on an object

ElementsElements Pure substancesPure substances that cannot be that cannot be

broken down chemically into broken down chemically into simpler kinds of mattersimpler kinds of matter

More than 100 elements More than 100 elements (92 (92 naturally occurring)naturally occurring)

90% of the mass of an 90% of the mass of an organism is composed organism is composed of 4 elements of 4 elements (oxygen, (oxygen, carbon, hydrogen and carbon, hydrogen and nitrogen)nitrogen)

Each element unique Each element unique chemical chemical symbolsymbol• Consists of Consists of 1-2 letters1-2 letters• FirstFirst letter is always letter is always

capitalizedcapitalized

AtomsAtoms

The The simplest particle ofsimplest particle of an elementan element that retains that retains all the properties of that all the properties of that elementelement

Properties of atomsProperties of atoms determine the structure determine the structure and properties of the and properties of the matter they composematter they compose

Our understanding of Our understanding of the structure of atoms the structure of atoms based on based on scientific scientific models,models, not observation not observation

The NucleusThe Nucleus

CentralCentral core core Consists of Consists of

positive charged positive charged protons and protons and neutral neutronsneutral neutrons

Positively Positively chargedcharged

Contains most of Contains most of the the mass of the mass of the atomatom

The ProtonsThe Protons All atoms of a given elementAll atoms of a given element have have

the the same number of protonssame number of protons Number of protonsNumber of protons called the called the

atomic numberatomic number Number of Number of protons balanced by an protons balanced by an

equalequal number of negatively number of negatively charged charged electronselectrons

The NeutronsThe Neutrons

The The number variesnumber varies slightly among slightly among atoms of the same elementatoms of the same element

Different number of neutrons Different number of neutrons produces produces isotopesisotopes of the same of the same elementelement

Atomic MassAtomic Mass Protons & neutrons are found in the Protons & neutrons are found in the

nucleus nucleus of an atomof an atom Protons and neutrons each have a mass of Protons and neutrons each have a mass of

1 amu (atomic mass unit)1 amu (atomic mass unit) The The atomic massatomic mass of an atom is found by of an atom is found by

adding the number of protons & neutrons adding the number of protons & neutrons in an atomin an atom

# of protons + # of neutrons =atomic # of protons + # of neutrons =atomic massmass

The ElectronsThe Electrons

Negatively chargedNegatively charged high energy high energy particles with particles with little or no masslittle or no mass

Travel at very high speedsTravel at very high speeds at various at various distances distances (energy levels)(energy levels) from the from the nucleusnucleus

Are located around the nucleusAre located around the nucleus

Periodic TablePeriodic Table

Elements are arranged by their Elements are arranged by their atomic number on the atomic number on the Periodic Periodic TableTable

The horizontal rows are called The horizontal rows are called PeriodsPeriods & tell the number of & tell the number of energy levelsenergy levels

Vertical groups are called Vertical groups are called Families Families & tell the outermost number of & tell the outermost number of electronselectrons

CompoundsCompounds

Most Most elements do elements do not exist by not exist by themselvesthemselves

Readily Readily combine combine with other with other elementselements in in a a predictable predictable fashionfashion

A A compoundcompound is a pure is a pure substance substance made up of made up of atoms of two or more atoms of two or more elementselements• The proportion of The proportion of

atoms are always atoms are always fixedfixed

Chemical formulaChemical formula shows the kind and shows the kind and proportion of atoms of proportion of atoms of each element that each element that occurs in a particular occurs in a particular compoundcompound

MoleculesMolecules are are the simplest part the simplest part of a substance of a substance that retains all of that retains all of the properties of the properties of the substance the substance and exists in a and exists in a free statefree state

Some molecules Some molecules are are large and large and complexcomplex

Chemical FormulasChemical Formulas

SubscriptSubscript after a symbol tell the after a symbol tell the number of atoms of each elementnumber of atoms of each element• HH2200 has 2 atoms of hydrogen & 1 has 2 atoms of hydrogen & 1

atom of oxygenatom of oxygen CoefficientsCoefficients before a formula tell before a formula tell

the number of moleculesthe number of molecules• 3O3O22 represents 3 molecules of oxygen represents 3 molecules of oxygen

or (3x2) or 6 atoms of oxygenor (3x2) or 6 atoms of oxygen

The tendency of The tendency of elements to combine elements to combine and form compoundsand form compounds depends on the depends on the numbernumber and and arrangementarrangement of of electrons in their electrons in their outermost energy leveloutermost energy level

Atoms are most stable Atoms are most stable when their outer most when their outer most energy level is filledenergy level is filled (when it has 8 (when it has 8 electrons)electrons)

Most atoms are not Most atoms are not stable in their natural stable in their natural statestate

Tend to reactTend to react (combine) (combine) with other atoms in with other atoms in order to become more order to become more stable (undergo stable (undergo chemical reactions)chemical reactions)

In In chemical reactionschemical reactions bonds are broken; atoms bonds are broken; atoms rearranged and new rearranged and new chemical bonds are chemical bonds are formed that store formed that store energyenergy

End ofDay OneNotes ?

Covalent BondsCovalent Bonds

Formed when two atoms Formed when two atoms share one or share one or more pairs of electronsmore pairs of electrons

Covalent BondingCovalent Bonding

In a In a COVALENT bondCOVALENT bond Electrons are sharedElectrons are shared between atoms between atoms

• The The numbernumber of of sharedshared atoms atoms depends depends onon how many are need to fill the octet how many are need to fill the octet rulerule

Cl2

Chlorineforms

acovalent

bondwithitself

ClClHowwilltwochlorineatomsreact?

ClClEach chlorine atom wants to gain one electron to achieve an octet

ClClNeither atom will give up an electron –It’s too close to filling the octet.

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!!

Ionic BondsIonic Bonds

Some atoms become stable by Some atoms become stable by losing losing or gaining electronsor gaining electrons

Atoms that Atoms that lose electronslose electrons are called are called positive ionspositive ions

Ionic BondsIonic Bonds 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+ _

FK+ _

The ionic bond is the attractionbetween the positive K+ ion

and the negative F- ion

Atoms that Atoms that gain electronsgain electrons are are called called negative ionsnegative ions

Because Because positive and negative positive and negative electricalelectrical charges attractcharges attract each each other ionic bonds formother ionic bonds form

SummarySummary

Atoms want to have 8 electrons in their Atoms want to have 8 electrons in their outer shell, so they will react to other outer shell, so they will react to other atoms to get 8 electronsatoms to get 8 electrons

Covalent bonds= two or more atoms Covalent bonds= two or more atoms SHARING electronsSHARING electrons

Ionic Bonds= When one atom STEALS Ionic Bonds= When one atom STEALS electrons from another, then there will be electrons from another, then there will be a positive and a negative ion which a positive and a negative ion which become attracted to each otherbecome attracted to each other

Questions?Questions?