IUPAC BOHR DIAGRAMS FOR ATOMS TYPES OF CHEMICAL BONDS MOLECULAR COMPOUNDS ◦ TYPES SIMPLE COVALENT COMMON NAME IONIC COMPOUNDS ◦ SIMPLE IONIC ◦ MULTIVALENT ◦ POLYATOMIC/COMPLEX ◦ HYDRATED IONIC ACIDS
International Union of Pure and Applied Chemists This is a global organization that sets the standards in chemistry. One job of the IUPAC is to give compounds SYSTEMIC NAMES.
Bohr diagrams, also called ENERGY LEVEL DIAGRAMS, are a means of drawing atoms in a 2-D manner. Keep in mind that atoms are actually 3-D, and there are more complex representations of atoms. Bohr models always include the NUCLEUS and the ELECTRON ENERGY LEVELS of an atom. LINK LINK
There are 3 types of SUBATOMIC PARTICLES found in the atom: PROTONS (p + ) ◦ Positively charged particles with a significant mass ◦ Atomic Number = Number of Protons ELECTRONS (e - ) ◦ Negatively charged particles with an insignificant mass ◦ Number of Electrons = Number of Protons NEUTRONS (n o ) ◦ Neutral particles with a significant mass ◦ Number of neutrons = Atomic Mass – Atomic Number
NUCLEUS ◦ Center of the atom, contains protons and neutrons ◦ The atomic mass is concentrated here ELECTRON ENERGY LEVELS ◦ Particular areas around the nucleus where electrons are likely to be found ◦ Electrons DO NOT exist BETWEEN energy levels ◦ 3 LEVELS: FIRST LEVEL (Closest to Nucleus)2 e- SECOND LEVEL 8 e- THIRD LEVEL (Outermost)8 e-
VALENCE LEVEL ◦ DEFINITION: Outermost energy level of an atom ◦ Electrons in this level are called VALENCE ELECTRONS ◦ Atoms with FULL valence shells are STABLE, meaning they will not bond with other atoms in normal conditions. ◦ The atoms of Group 18, the Noble Gases, have full valence levels. ◦ Atoms that do not have full electron energy levels are unstable and must GAIN, LOSE, or SHARE electrons to become stable.
ATOMIC NUMBER ◦ Located in the top of each element box on the periodic table. ◦ ATOMIC NUMBER = # OF PROTONS ATOMIC MASS (MOLAR MASS) ◦ Located in the bottom of each element box on the periodic table. ◦ Round it off for calculations. ◦ ATOMIC MASS = # OF PROTONS + # OF NEUTRONS
EXAMPLE: DRAW BOHR DIAGRAMS FOR: Li – lithium atom ◦ ATOMIC # = _____________ ◦ ATOMIC MASS = _____________ ◦ # p + = ________________________ ◦ # e - = ________________________ ◦ # n o = ________________________
EXAMPLE: DRAW BOHR DIAGRAMS FOR: Ne – neon atom ◦ ATOMIC # = _____________ ◦ ATOMIC MASS = _____________ ◦ # p + = ________________________ ◦ # e - = ________________________ ◦ # n o = ________________________
EXAMPLE: DRAW BOHR DIAGRAMS FOR: S – sulfur atom ◦ ATOMIC # = _____________ ◦ ATOMIC MASS = _____________ ◦ # p + = ________________________ ◦ # e - = ________________________ ◦ # n o = ________________________
Do worksheet in booklet on following page!!! For complete answers be sure to do the following: ◦ Write in the atomic number and mass number. ◦ Write the name of the atom in the bottom of the square. ◦ Include protons and neutrons in the nucleus of the atom. ◦ Write electrons in the energy levels outside the nucleus.
CHEMICAL BONDS ◦ DEFINITION: A force of attraction between atoms. ◦ There are 2 TYPES of Chemical bonds Covalent Ionic
COVALENT BONDS ◦ AKA: molecular bonds ◦ “co” – together/sharing, “valent” – outer shell ◦ DEFINITION: A SHARING of ELECTRONS between 2 atoms BETWEEN a two or more NONMETALS ◦ Solutions of covalently bonded substances are NON-ELECTROLYTIC.
IONIC BOND ◦ DEFINITION: A TRANSFER of ELECTRONS between two atoms BETWEEN a METAL and a NONMETAL ◦ Solutions of ionic bonded substances are ELECTROLYTIC. COMPOUNDS consist of atoms or ions of two or more elements bonded together.
Forms when 2 or more NONMETALS share electrons in COVALENT BONDS. 2 TYPES: ◦ BINARY Molecular Compounds ◦ TRIVIAL NAME Molecular Compounds
Also called SIMPLE molecular compounds. Binary Molecular Compounds use IUPAC prefixes: ◦ We will write these prefixes in the following table. NumberPrefix 1mono 2di 3tri 4tetra 5penta 6hexa 7hepta 8octa 9nona 10deca
RULES: 1.Write NAMES of elements, with the 2 nd element ending in “-ide”. 2.Add PREFIXES to indicate HOW MANY ATOMS of each element. 3.Do NOT use the prefix “mono” for the 1 st element, only with the 2 nd element.
N 2 O 4 ________________________ P 2 O 5 ________________________ CCl 4 ________________________
RULES: 1.Write ELEMENT SYMBOLS for each element in the compound. 2.Use the PREFIX in the name to determine NUMBER OF ATOMS, and write that number as a SUBSCRIPT next to the symbol (no subscript for 1 atom).
Also called COMMON NAME molecular compounds. There are SOME molecular compounds that go by their COMMON NAMES, and we must memorize these names. FORMULATRIVIAL/COMMON NAME O3O3 ozone H2OH2Owater H2O2H2O2 hydrogen peroxide NH 3 ammonia CH 4 methane CH 3 OHmethanol C 2 H 5 OHethanol C 6 H 12 O 6 glucose C 12 H 22 O 11 sucrose
Complete the NEXT THREE SHEETS in your handout for HOMEWORK. Refer to the following notes for help: ◦ FIRST SHEET Given Name, Write Formula Notes ◦ SECOND SHEET Given Formula, Write Name Notes ◦ THIRD SHEET Everything! Watch out for those common name molecular compounds!!!
IONS ◦ RECALL: AS mentioned earlier, atoms other than the NOBLE GASES are unstable, and need to GAIN, LOSE, or SHARE ELECTRONS to become more stable. If they SHARE electrons, this forms a COVALENT BOND to another atom. If they LOSE or GAIN electrons, atoms become IONS and form IONIC BONDS with other atoms. OCTET RULE ◦ Atoms that have an octet of valence electrons are STABLE and UNREACTIVE.
Ions are charged atoms that have lost or gained electrons to achieve the valence configurations of a noble gas. TWO TYPES: ◦ CATIONS: POSITIVE ions that are formed from a LOSS of electrons. It has more PROTONS than ELECTRONS and therefore has a net POSITIVE charge. METALS form cations. MEMORY TOOL: t in “cation” resembles a “+” sign EXAMPLE: lithium ion Li + 1+ charge
◦ ANIONS: NEGATIVE ions that are formed from a GAIN of electrons. It has more ELECTRONS than PROTONS and therefore has a net NEGATIVE charge. change the ending of the name of anions to -ide NONMETALS form anions. MEMORY TOOL: A Negative ION EXAMPLE: fluoride ion F - 1- charge LINK LINK
METALS ◦ ATOMS of METALS will LOSE electrons to become CATIONS. ◦ ATOMS with 1, 2, or 3 VALENCE electrons will LOSE these electrons to form 1+, 2+, or 3+ ions respectively. ◦ GROUP 1 ATOMS – ALKALI 1 valence electrons(s) (will lose 1 to become stable) 1 + ion ◦ GROUP 2 ATOMS – ALKALINE EARTH 2 valence electrons(s) (will lose 2 to become stable) 2 + ion ◦ GROUP 13 ATOMS 3 valence electrons(s) (will lose 3 to become stable) 3 + ion
NONMETALS ◦ ATOMS of NONMETALS will GAIN electrons to become ANIONS. ◦ ATOMS with 5,6, or 7 VALENCE electrons will GAIN these electrons to form 3-, 2-, or 1- ions respectively. ◦ GROUP 15 ATOMS 5 valence electrons(s) (will gain 3 to become stable) 3 - ion ◦ GROUP 16 ATOMS 6 valence electrons(s) (will gain 2 to become stable) 2 - ion ◦ GROUP 17 ATOMS - HALOGENS 7 valence electrons(s) (will gain 1 to become stable) 1 - ion ◦ GROUP 18 ATOMS - NOBLE GASES FULL outer valence levels
Form when at least 1 METAL AND 1 NONMETAL transfer electrons in an IONIC BOND. Metals will become CATIONS and LOSE electrons and nonmetals will become ANIONS and GAIN electrons. These ions, with opposite charges, attract and form IONIC BONDS. Unlike covalent bonds, these bonds are not “ACTUAL BONDS,” but forces of attraction between oppositely charged ions. They stay together in a CRYSTAL LATTICE.
Example: NaCl (Draw on your sheet) Cl - Na + Cations are surrounded by anions and vice versa Also refer to Figure 4, p. 189
“Binary” Only 2 types of ions involved. SIMPLE IONIC COMPOUNDS ◦ Simple ionic compounds are composed of a metal ion (+) and a nonmetal ion(-). GIVEN FORMULA, WRITE NAME ◦ RULES: 1.Write the name of the CATION before the ANION (Be positive before being negative ) 2.Change the ending of the ANION name to “-ide” 3.Do not use CAPITALS, Do not use PREFIXES!
EXAMPLE: ◦ MgBr 2 _________________________________ ◦ KCl_________________________________ ◦ Na 2 S_________________________________ ◦ Mg 3 P 2 _________________________________ ◦ Ba 3 N 2 _________________________________ WHAT’S WRONG WITH THE FOLLOWING NAMES FOR BaS? ◦ barium sulfur____________________________ ◦ Barium Sulfide____________________________ ◦ barium sulfuride____________________________
Do the following sheet in the booklet for homework: Follow rules for: ◦ “GIVEN FORMULA, WRITE NAME” for Ionic Compounds.
GIVEN NAME, WRITE FORMULA ◦ RULES: 1.Write element symbols. 2.Look up the ION CHARGE on the periodic table. 3.Use the “crossover” method to determine the numbers of each ion in the compound. 4.Ion ratios are always in the lowest common multiple. 5.Ion charges must add up to “zero” overall.