The Structure of AtomWhat is a mineral ? a naturally occurring solid that has a define internal structures and specific chemical composition in a periodically repeating arrangement of atoms. eg QUARTZ, EMERALDS, ETC Mineral : - naturally forming - inorganic - crystalline solid - known chemical composition - known physical properties Different Mineral and not Mineral Quartz is a mineral ORDERLY ARRANGEMENT OF IONS OR ATOMS INTO A LATTICE WORK OF REPEATED THREE – DIMENSIONAL UNITS Glass is not a mineral GLASS IS NOT A MINERAL – SUDDEN COOLING OF MOLTEN ROCK RESULTS IN LACK OF ORDERLY ARRANGEMENT Ilustrasi dari batuan sampai atom Biotite Feldspars Plagioclase Drusy Quartz on Barite Quartz Granite Silicon Quartz Oxygen ETC Rock : an aggregate composed of one or more minerals . COLD OR REACTION WITH OTHER 112 ELEMENTS.Definitions Element : a substance that cannot be broken down into other substances by HEAT. eg QUARTZ. ELEMENTS : Atom 92 NATURAL. EMERALDS. 20 LAB CREATION : the smallest possible particle of an element that still retains the properties of that element Compounds : One or more elements combine in specific proportions to form chemical compounds EX: QUARTZ Si O2 (ONE Si ATOM 2 OXYGEN ATOMS) Mineral : a naturally occurring solid that has a definite internal structures and specific chemical composition in a periodically repeating arrangement of atoms. IONS IONS: ELECTRICALLY CHARGED PARTICLE Cations : form from metals because they have a low Ionization energy & will readily give up electrons to obtain the electron configuration of a noble gas Anions : form from non-metals because they have low Electron affinity and will readily accept electrons to obtain the electron configuration of a noble gas Electrons are transferred from the Cation to the Anion and the charged ions attract each other . . 00000001CM) ATOMS CONSISTS OF OUTER ELECTRONS NUCLEUS – COMPOSED OF PROTONS & NEUTRONS CHARGE OF A PROTON = +1---------1.MP= ME * 1836 Nucleus NUMBER OF PROTONS (Z) = ATOMIC NUMBER Protons NUMBER OF ELECTRONS = NUMBER OF PROTONS Neutrons Shells Electrons ISOTOPES : ATOMS OF SAME ELEMENT WITH DIFFERENT NEUTRON NUMBER ( SAME Z BUT DIFFERENT ATOMIC WEIGHT) .NEUTRAL 238 U MASS ------.AMU 92 = 238 AMU ELECTRONS TRAVEL AROUND THE NUCLEUS ME =MP/1836 ------.The Atom Components DIAMETER ~ 10-8 CM (0.60*10-19 C MASS OF A PROTON = 1.67*10-24 G =1 ATOMIC MASS UNIT (AMU) NEUTRONS --------. How small is an atom? Atoms are 1/10000000000 of a meter in length….SMALL! . . The Atom Structure . The Quantum View of Atom . The Atomic Number . The PeriodicTable . The Atomic Mass . The Atomic Sizes . DIAMETER OF IONS . NEXT ENERGY LEVEL 32 ELECTRONS Orbiting electrons in energy levels Nucleus .ENERGY LEVEL ENERGY LEVEL : SPECIFIC REGION OF SPACE AROUND THE NUCLEUS WHERE AN ELECTRON MOVES.LOWEST ENERGY LEVEL 2 ELECTRONS --.NEXT ENERGY LEVEL 18 ELECTRONS --. ELECTRONS FILL THE LOWEST ENERGY LEVELS BEFORE THEY START FILLING HIGHER LEVELS --.NEXT ENERGY LEVEL 8 ELECTRONS --. ENERGY LEVEL DIAGRAM-H ATOM . ENERGYLEVEL DIAGRAM – He ATOM . ENERGY-LEVEL DIAGRAM – Li ATOM . ENERGY-LEVEL DIAGRAM – Na ATOM . F is highest 9.5 . Electron Affinity .Electronegativity Electronegativity is the ability of an atom to attract toward itself the electrons in a chemical bond.relative.measurable. Cl is highest X (g) + e- X-(g) Electronegativity . Electronegativity The amount to which an atom attracts electron density . 9.5 . 5 .Classification of bonds by difference in electronegativity Difference Bond Type 0 Covalent 2 0 < and <2 Ionic Polar Covalent Increasing difference in electronegativity Covalent Polar Covalent share e- partial transfer of e- Ionic transfer e- 9. CHEMICAL BONDING BONDING : ATOMS COMBINE TO FORM CHEMICAL COMPOUNDS IN A VARIETY OF WAYS KNOWN AS BONDING. TEND TO ACCEPT ATOMS WITH 3 OR 4 OR 5 ELECTRONS. GAINING OR SHARING OUTER ELECTRONS ATOMS WITH 1 OR 2 ELECTRONS. TWO FACTORS THAT DETERMINE WHICH ATOMS WILL UNITED WITH OTHERS: 1. RESULTING COMPOUND SHOULD BE NEUTRAL OCTET RULE : Atoms tend to gain or lose electrons in when bonding to give 8 electrons in their valence shells. TEND TO GIVE UP ATOMS WITH 6 OR 7 ELECTRONS. CHEMICAL STABILITY IS ATTAINED ATOMS BIND WITH OTHER ATOMS BY LOSING. TEND TO SHARE INERT GAS . EACH ATOM SHOULD ACHIEVE CHEMICAL STABILITY 2. WHEN OUTER-MOST ENERGY LEVEL IS FILLED. Chemical Bonding ● Ionic bond ● Hydrogen bond ● Covalence bond ● Metallic bond ● van der Waals bond . Example: NaCl Na (metal) unstable Cl (nonmetal) unstable electron Na (cation) stable + Coulombic Attraction - Cl (anion) stable 8 .IONIC BONDING • • • • Occurs between + and . Requires electron transfer. Large difference in electronegativity required.ions. IONIC BONDING . 9 K 0.1 Li 1. 3rd edition.5 O F 3.0 Na 0.2 Ca 1.7.5 At 2.9 Fe 1.5 4. 3rd edition. Callister 6e.8 As 2.9 Give up electrons Acquire electrons Adapted from Fig.7 NaCl MgO CaF 2 CsCl Be 1.7 Fr 0.8 I 2.8 Rb 0. The Nature of the Chemical Bond.8 Ni 1.0 Mg 1. 2.8 Cs 0.0 Br 2. 9 . 2.8 Zn 1.2 He Ne Ar Kr Xe Rn - Ra 0.0 Sr 1. Copyright 1939 and 1940. (Fig.5 Cr 1.0 Cl 3.7 is adapted from Linus Pauling.0 Ti 1.EXAMPLES: IONIC BONDING • Predominant bonding in Ceramics H 2.6 Ba 0. Copyright 1960 by Cornell University. 4. OR 5 ELECTRONS SHARE WITH OTHER SIMILARLY EQUIPPED ATOMS *COVALENT BONDS ARE GENERALLY STRONGER THAN ANY OTHER BOND 10 . 2.COVALENT BONDING • Requires shared electrons • Example: CH4 C: has 4 valence e. Callister 6e.10. needs 4 more CH 4 H: has 1 valence e. ATOMS WITH 3. H C H shared electrons from carbon atom H shared electrons from hydrogen atoms Adapted from Fig. needs 1 more H Electronegativities are comparable. These two valence electrons forming the bond are shared by both atoms.SINGLE COVALENT BOND A hydrogen atom and the oxygen atom each donate one valence electron to form a chemical bond. resulting in a SINGLE COVALENT BOND. H O . forming a DOUBLE COVALENT BOND. but as a molecule of two oxygen atoms. These two oxygen atoms share two pairs of valence electrons (four valence electrons total) between them. .DOUBLE COVALENT BOND Air. Oxygen does not exist as a single oxygen atom. contains oxygen. too. TRIPLE COVALENT BOND Another component of air is nitrogen. Like oxygen. The two nitrogen atoms in a molecule of nitrogen share three pairs of valence electrons (six valence electrons total) to form a TRIPLE COVALENT BOND. nitrogen does not exist as a single nitrogen atom. . but as a molecule made up of two nitrogen atoms. Lengths of Covalent Bonds Bond Type Bond Length (pm) C-C 154 C C 133 C C C-N 120 C N 138 C N 116 143 Bond Lengths Triple bond < Double Bond < Single Bond 9.4 . 8 Ni 1.5 Si 1.0 Rb 0.8 F 4. 2.8 Cs 0.0 Ba 0.8 Be 1.5 Mg 1.8 Ga 1.8 2.7.1 Li 1.EXAMPLES: COVALENT BONDING H2 H 2. 2.9 • • • • c o lu m n IV A H2O C(diamond) SiC Ti 1. Molecules with nonmetals Molecules with metals and nonmetals Elemental solids (RHS of Periodic Table) Compound solids (about column IVA) 11 .0 F2 He O 2.8 Pb 1.7 Ra 0. Copyright 1939 and 1940. Copyright 1960 by Cornell University.9 Fr 0. 3rd edition. (Fig.6 C 2.6 Fe 1.2 Ne - Cl2 Ar Kr Xe Rn - GaAs Adapted from Fig.8 Ge As 1.0 Sn 1.9 K 0.8 I 2.5 Cr 1.7 is adapted from Linus Pauling.0 Br 2. The Nature of the Chemical Bond. Callister 6e.8 Zn 1.0 Cl 3.5 At 2.2 Ca 1.0 Na 0.7 Sr 1. 3rd edition. The Hydrogen Bond • hydrogen bond occurs when a hydrogen atom that is bound to an electronegative atom is also attracted to another electronegative atom . 2. • Primary bond for metals and their alloys . or 3 from each atom).The Metallic Bond METALLIC BONDING: ATTRACTION OF NEGATIVELY CHARGED ELECTRON CLOUD TO A CLUSTER OF POSITIVELY CHARGED NUCLEI. Sea of electrons • Arises from a sea of donated valence electrons (1. Van der Waals bond Van der Waals: Waals Weak forces of electrostatic attraction such as between sheets of atoms held together by ionic or covalent bonds Bond occur between atoms and molecules that are very close together and result from “charge asymmetry” in electron clouds. . or The bonds between the molecules that allow sliding and rupture to occur are called van der Waal forces. Nuwun .