Elements Simplest form of matter that retains its properties Known by common names and abbreviations

ElementsSimplest form of matter that retains its

propertiesKnown by common names and abbreviations

Compounds• Made of two or more elements chemically

combined in definite proportions– Law of definite proportions: pure compounds always

have the same ratio of elements H2O = 2 Hydrogen for every 1 Oxygen

(Chemical Formula)

• Two Types:①Ionic Compounds②Molecular Compounds (Molecules)

Paper Clip Lab

• Elements vs. Compounds vs. Mixtures

Ionic Compounds• Made up of Ions: Charged atoms

Cations: Positive chargeEx: Na (Atom) Na+ (Cation)

11 protons (+) 11 protons (+)11 electrons (-) 10 electrons (-)

Anions: Negative ChargeEx: Cl (Atom) Cl- (Anion)

17 protons (+) 17 protons (+)17 electrons (-) 18 electrons (-)

Ions Vs. Atoms

• There are chemical differences between ions and atoms….

Na+ vs. NaUniversity of Nottingham http://www.periodicvideos.com/videos/011.htm

Army disposing of Na http://www.youtube.com/watch?v=HY7mTCMvpEM

Ions and Periodic Table

2 Types of Ions• Monatomic Ions: Single elements

Na+ Zn2+ Br- Cl- O2-

• Polyatomic Ions: Two or more different elementsNH4

+ CO32- CrO4

2- Cr2O72-

See your handout for the list

Ionic Compounds• Cation + Anion = Ionic Compound

Na+ + Cl- = NaCl Ni2+ + 2(IO3

-) = Ni(IO3)2

The positive cation and negative anion attract each other to form neutral compound

Usually solids with high melting and boiling points

Usually form from metal and nonmetal

Naming Ionic Compounds• Binary Ionic Compounds: 2 different ions

K+ + Cl- KCl

①Cation is ALWAYS first ②Net charge is ALWAYS zero③Cation name doesn’t change.④Change anion name by using the “ide” ending

KCl = Potassium Chloride

Naming Ionic Compounds①NaCl =

②MgO =

③KF =

④CaBr2 =

Naming Ionic Compounds• Some elements (called transition metals) can form

more than one type of positive ion. The positive charge of the ion is then indicated by a roman numeral.

Fe2+ = iron(II) Fe3+ = iron(III)Cu+ = copper(I)Cu2+ = copper(II)

Naming Ionic Compounds①CuBr =

②PbCl2 =

③FeN =

④CrP =

Naming Ionic Compounds• Polyatomic ions:– Have special names– Are treated as one unit (they don’t break apart)– Most end in “ite” or “ate”

Ba2+ + CO32- BaCO3

Barium Carbonate Barium carbonate

Naming Ionic Compounds①FePO4 =

②CaCrO4 =

③NaNO3

④SnSO4

Naming Ionic Compounds①Zinc chloride =

②Iron(II) oxide =

③Tin(IV) sulfite =

④Aluminum hypochlorite =

Molecule• Neutral groups of non-metallic elements joined by

covalent bonds (electrons are shared) NO IONS – NO CHARGE

• Low melting and boiling points– Liquids and gases at room temperature

• Ex: H2O, CO2, O2, and Cl2

Naming Molecular Compounds• Name them in the order that they appear– Element with more positive chemical nature will be first• “More positive” means towards the left side of periodic table

– Second element: drop the last syllable and add “ide”

• If there is more than one atom of an element, add a numerical prefix:

CO = Carbon MonoxideCO2 = Carbon Dioxide

N2O3 = Dinitrogen Trioxide

Naming Molecular Compounds①Dinitrogen monoxide =

②Silicon carbide =

③N2O4 =

④Cl2O8 =

Naming Acids and Bases• Acid: Produces hydrogen ion (H+) when dissolved in

H2O– Formula = (H+ to balance the anion charge) + (anion)

Ex: H2S HCl

• Base: Produces hydroxide ion (OH-) when dissolved in H2O• Formula= cation metal + hydroxide ion to balance charge

Ex: NaOH Al(OH)3

Naming Acids• When the anion….– Ends with “ide”:

acid name begins with “hydro”the suffix “ic” is added to the anion

Ex: HCl = hydrochloric acid- Ends with “ite”:

the suffix “ous” is added to the anionEx: H2SO3 = sulfurous acid

- Ends with “ate”:the suffix “ic” is added to the anion

Ex: HNO3 = nitric acid

Naming Bases• Named the same way as ionic compounds– Al(OH)3 = aluminum hydroxide

– Fe(OH)3 = iron(III) hydroxide

Naming Acids and Bases①H2CO3 =

②Phosphoric acid =

③KOH =

④Strontium hydroxide =