Chemical Names and Chemical Names and FormulaFormula

Chemical Names and Chemical Names and FormulaFormulaChemistryChemistry

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Periodic Table• There are over 90 naturally

occurring elements/atoms and about 25 elements made in the lab.

• Various combinations of atoms can be formed, and which such diversity we need a way to name and communicate these variations

Periodic table• Elements are arranged in row and

columns on the: Periodic table• Hydrogen, the smallest and

lightest element in top right corner• Helium is atomic number 2

Atomic Numbers• Krypton

Calculate• For any element:• Number of Protons = Atomic Number• Number of Electrons = Number of Protons = Atomic

Number• Number of Neutrons = Mass Number - Atomic Number• For krypton: Number of Protons = Atomic

Number = 36• Number of Electrons = Number of Protons =

Atomic Number = 36• Number of Neutrons = Mass Number - Atomic

Number = 84 - 36 = 48

Periodic Table• A column of elements in the periodic

table is known as a group– There are 18 groups– Group 1A:

• H• Li• Na• K• RB• Cs

Breakdown of each group

• Group 1=Alkali Metals• Group 2= Alkaline Earth Metals• Group 3-12= Transition metals• Group 13,14 & 15= Other metals• Metalloids=Boron diagonal down over and down over( A

big L)• Group 14-16 =Non Metals• Group 17= Halogens (salt formers)• Group 18= Noble gases• Rare Earth Metals= Man made elements inserted in the

transition metal at 56 and 88• Chemical Elements.com - Noble Gases

Alkali Metals/Representative

metals (A)• The illustrate the entire range of

chemical properties– Both metals and non metals– They do not include transition metals

or inner transition metals (man made ones)

Metallic Metals• A Groups (1, 2 13-18)• Have high luster when cleaned• High electrical conductivity• Ductile

– Can be drawn into wires• Malleable

– Beaten into sheets (dyes at GM plants)

Groups• 1A starts with H or Li

• Hydrogen is special It is a non metal in group 1A

• 2A starts with Be• 3A starts with B• 4A starts with C• 5A starts with N• 6A starts with O• 7A starts with F

Transition Metals (B)• B group elements• Inner transition metals (rare earth

metals).

Non Metallic• Elements that are:

– Non lustrous– Poor conductors of electricity– Some are gases– Others are brittle solids and some

liquids at room temperature

Semi Metals or Metalloids

• Elements with the properties of both metals and nonmetals– Silicon

• Found in transistors– Good semi conductor– Conducts electricity in a special way

• Breast implants (cheap ones)

Atoms and Ions• All elements are composed of atoms of the

same kind– Atomic Theory (review)– An atom is electrically neutral because it has an

equal number of protons and electrons• Na atomic number is 11 and has 11 protons and is

positively charged, has 12 neutrons• Because Neutrons have no charge the total charge of

Na is (+11)+ (11)=0• When elements form compounds they can gain or lose

electrons, and when the number of electrons is not equal to the number of protons then the atom becomes a

– Ion

IOns• Are atoms or groups of atoms that

have a positive or negative charge• Formed when atoms gain or lose

electrons

Positive ions• Metals tend to form positive ions by

losing one or more electrons– Cation

• Any atom or group of atoms with a positive charge• Na ion is form by the loss of one electron from the

Na atom• Sodium ion has 11 protons and 10 electrons it has

a charge of 1+• Atomic charges are written with the number

followed by a sign– Na1+ or Na+ (always write ions this way)– If the number is 1 it can be omitted

Ions• Mg ions are formed differently

because they have different valence electrons (electrons in outer shell)

• Mg has a charge of 2+ so it has 12 protons, and 10 electrons

Negative Ions• Nonmetallic elements tend to gain one

or more electrons• Anions

– Atoms or groups of atoms with a negative charge

– Anions have more electrons (unlike cations).

– Cl ions has 17 protons and 18 electrons– It has a charge of -1– Oxide ion has a charge of -2

Compounds• Are pure substances the differ from elements

because they contain more than one kind of atom.

• Law Of Definite Proportions: In any chemical compound the elements are always combined in the same proportion by mass

• A Molecule is a neutral group of atoms that act as a unit. All molecules of a given compound are neutral.

• Compounds that are composed of molecules are molecular compounds.

Law of Definite Proportions

• MgS is a compound. IF we have 100g of this compound– It will always contain:

• 43.13g of Mg• 56.87g of S

• This mass ratio will never change no matter how much you have

Chemical Formulas• There are more than 4 million chemical

compounds.• Chemical Formulas

– Some are molecular– Some are ionic

• A chemical formula shows the number and kinds of atoms present in a molecule.

• A molecular formula shows the number and kinds of atoms present in a molecule of a compound– Example = H2O CO2 C2H6 C2H6O

Formulas and Names of Common Metals Ions with more than 1 ionic charge

• Formula Name Stock Name Classical Name

• Cu1+ Copper (I) Ion Cuprious ion• Cu2+ Copper (II) Ion Cupric Ion• Fe2+ Iron (II) Ion Ferrous Ion• Fe3+ Iron (III) Ion Ferric Ion• Hg2 Mercury (I) Ion Mercurrous Ion• Hg2+ Mercury (II) Ion Mercuric Ion

• Review Table 5-3

Rules for naming• Compounds that give OH- ions

• Bases

• Compounds that give H+ ions• Acids

• ite ending• Will always indicate less oxygen

• ate ending• Will always indicate more oxygens

Binary ionic compounds

• Composed of two elements– Always cation and anion– They always have ide ending– Name metal first then put ide ending

on nonmetal• Sodium chloride

– Monoatomic always have ide ending

Binary Ionic compounds

• Name by writing name of cation followed by name of anion (ide ending).

Ternary Ionic Compounds

• Contain 3 different elements• They usually contain one or more

polyatomic ions• First write down formulas of ions• Then balance charges• An ate or ite ending on polyatomic ion• Calcium nitrate

Acids

• Are compounds that give off hydrogen ions when dissolved in water.

• When anion ends in ide the acid name begins with prefix hydro. The stem (nonmetal in most cases ends with ic)

• HCl= hydrochloric acid

rulesAnion ending Example/

StemAcid Name Example

ide Cl-Chloride

Hydro (stem) ic acid

Hydrochloric acid

ite SO2-3

Sulfite(stem) ous acid

Sulfurous acid

ate NO-3

nitrate

(stem) ic acid Nitric acid