Formulas

Objective 4 TEK 7 The student knows relationships exist between properties of matter and its components.(D) Relate the chemical behavior of an element including bonding, to its placement on the periodic table.

Cool!

I should have paid more attention to my teacher!!!!

TAKS was important.

IonsIonsIonsIons• CationCation: A positive ion : A positive ion

• MgMg2+2+, NH, NH44++

• AnionAnion: A negative ion : A negative ion

• ClCl, SO, SO4422

• Ionic BondingIonic Bonding: Force of attraction : Force of attraction between oppositely charged ions.between oppositely charged ions.

Predicting Ionic ChargesPredicting Ionic Charges

Group Group (IA) (IA) 1:1:Lose 1 electron to form Lose 1 electron to form 1+1+ ions ions

HH++ LiLi++ NaNa++ KK++

Predicting Ionic ChargesPredicting Ionic Charges

Group Group (IIA)(IIA) 22:: Loses 2 electrons to form Loses 2 electrons to form 2+2+ ionsionsBeBe2+2+ MgMg22

++CaCa2+2+

SrSr22

++BaBa2+2+

Predicting Ionic ChargesPredicting Ionic ChargesGroup (IIIA) 13Group (IIIA) 13::

Loses 3 Loses 3 electrons to form electrons to form 3+3+ ions ions

BB3+3+ AlAl3+3+ GaGa3+3+

Predicting Ionic ChargesPredicting Ionic ChargesGroup (IVA) 14Group (IVA) 14::

Lose 4 Lose 4 electrons or gain electrons or gain 4 electrons?4 electrons?

ManyMany Group IVA Group IVA (14) elements (14) elements rarely form ions.rarely form ions.

Predicting Ionic ChargesPredicting Ionic Charges

Group (VA) 15Group (VA) 15::Gains 3 electrons Gains 3 electrons to form to form 3-3- ions ions

NN3-3-

PP3-3-

AsAs3-3-

Nitride

Phosphide

Arsenide

Predicting Ionic ChargesPredicting Ionic Charges

Group (VIA) 16Group (VIA) 16::

Gains 2 electrons Gains 2 electrons to form to form 2-2- ions ions

OO2-2-

SS2-2-

SeSe2-2-

OxideOxide

SulfideSulfide

SelenideSelenide

Predicting Ionic ChargesPredicting Ionic Charges

Group (VIIA) 17Group (VIIA) 17::

Gains 1 electron Gains 1 electron to form to form 1-1- ions ions

FF1-1-

ClCl1-1-

BrBr1-1-Fluoride

Chloride

Bromide

II1-1- Iodide

Predicting Ionic ChargesPredicting Ionic Charges

Group (VIIIA) 18Group (VIIIA) 18::

Stable Noble Stable Noble gases gases do notdo not form ions!form ions!

Predicting Ionic ChargesPredicting Ionic Charges

Groups 3 - Groups 3 - 1212:: Many Many transitiontransition elements elements have more than one possible oxidation have more than one possible oxidation state. Roman numerals are used to state. Roman numerals are used to indicate the oxidation state indicate the oxidation state

Iron(II) = Fe2+ Iron(III) = Fe3+

Predicting Ionic ChargesPredicting Ionic ChargesGroups 3 - Groups 3 - 1212::

Some Some transitiontransition elements elements have only one possible oxidation state.have only one possible oxidation state.

Zinc = Zn2+ Silver = Ag+

Writing Ionic Compound Writing Ionic Compound FormulasFormulas

Example: Iron(III) with chloride1. Write the formulas for the cation and anion, including CHARGES!

FeFe3+3+ClCl--2. Check to see if charges are balanced.

3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.

Not balanced!

33FeFe3+3+ ClCl--

Balanced!Iron(III) chloride

4. Name the ions

Example: Barium with nitrateBarium with nitrate

1. Write the formulas for the cation and anion, including CHARGES!

BaBa2+2+ NONO33--2. Check to see if charges are

balanced.

3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.

Not balanced!

( )( )22

BaBa2+2+ NONO33--

Balanced!Barium Barium nitratenitrate

4. Name the ions

Example: Ammonium with sulfate

1. Write the formulas for the cation and anion, including CHARGES!

NHNH44++ SOSO44

2-2-2. Check to see if charges are balanced.

3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.

Not balanced!

( )( ) 22NHNH44++ SOSO44

2-2-

Your Turn!

Ammonium sulfate4. Name the ions

Example: Aluminum with sulfide1. Write the formulas for the cation and anion, including CHARGES!

AlAl3+3+ SS2-2-

2. Check to see if charges are balanced.

3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.

Not balanced!

22 33AlAl3+3+ SS2-2-

Aluminum sulfide

4. Name the ions

Example: Magnesium with carbonateMagnesium with carbonate

1. Write the formulas for the cation and anion, including CHARGES!

MgMg2+2+ COCO332-2-2. Check to see if

charges are balanced.

They are balanced!

Magnesium Magnesium carbonatecarbonate

4. Name the ions

Example: Zinc with hydroxide

1. Write the formulas for the cation and anion, including CHARGES!

ZnZn2+2+ OHOH--

2. Check to see if charges are balanced.

3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.

Not balanced!

( )( ) 22ZnZn2+2+ OHOH--Zinc hydroxide

4. Name the ions

Example: Calcium with phosphate

1. Write the formulas for the cation and anion, including CHARGES!

CaCa2+2+ POPO443-3-

2. Check to see if charges are balanced.

Not balanced!

Calcium phosphate

CaCa2+2+ POPO443-3-

2233( )( )

4. Name the ions

3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion.

Chemical Formulas and Chemical Compounds

Heart cell rhythm depends on the opening and closing of a complex series of valves on the cell membrane, called ion channels. Some valves let certain ions like potassium (K+) flow out, others let different ions like sodium (Na+) flow in. There are also pumps that actively move ions one direction or another.