Bonding and Chemical Reactions Compounds and Molecules
Chemical Bond: forces that hold atomstogether in a compound. Chemical Structure: the arrangement of atomsin a substance Bond length: distance between nucleus of2 atoms Bond Angle: angle the bonds between 3 ormore atoms form Chemical Structure compounds with networks are strong solids
ex: diamond, quartz, many rocks networked compounds havemelting andboiling points ex: salts, rocks, diamonds Chemical Structure Some compounds are made of molecules
ex: H2, O2, N2, CO2 are all gases with weakattraction hydrogen bonds are very strong Bonding Atoms form bonds so each atom has 8 valence electrons.
This is known as stable. Ionic Bonding Ionic Bonds: between oppositely chargedatoms; usually on opposite sides of the periodictable (nonmetal and a metal) transfer electrons form networks, not molecules conduct electricity Covalent Bonds Covalent Bonds: share electrons; usuallybetween 2 elements close on the periodic table(2 nonmetals) nonpolar covalent bond: e- shared equally polar covalent bond: e- shared unequally Metallic Bonding sea of electrons: electrons can float freelybetween atoms; allows metals to conductelectricity well Compound Names and Formulas
Compounds have specific names soyou can tell how many and what atomsare in the compound/molecule. Ionic compounds MUST have a total charge of zero!!
Ionic Naming Cations are just the name of the element Anions have -ide at the end of the elementsname Sodium Chloride Cation is ALWAYS FIRST Anion is ALWAYS LAST Ionic compounds MUST have a total charge of zero!! Na+1 + Cl-1 = NaCl = 0 charge! Transition Metal Naming
Transition metals show their charges as RomanNumerals because they can change charge!! FeO = Fe+2 + O-2 Iron (II) Oxide Fe2O3 = Fe+3 + O-2 Iron (III) Oxide What is the formula for Lithium Oxide? What is the name for CuCl2? If you only have 1 cation, you dont need a prefix!
Covalent Naming To name covalent compounds, you must put aprefix in front of the elements name. mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- If you only have 1 cation, you dont need a prefix! What is the name of H2O? Formulas Empirical Formula: smallest whole-numberratio of atoms in a compound Molecular Formula: how many atoms are in amolecule of a compound GLUCOSE EmpiricalFormula MolecularFormula CH2O C6H12O6 Chemical Reactions Rearrange atoms Involve changes in energy
Exothermic: release energy (heat, fire, fizz, etc) Endothermic: absorb energy (drop in temp.) methane and oxygen yield carbon dioxide and water
Chemical Equations methane and oxygen yield carbon dioxide and water ___ CH4 + ___ O ___CO2 + ___ H2O Reactants Products Balance the reaction. ___ Mg + ___ O ___MgO Balance the reaction. ___ H2O ___H2O + ___ O2 Reaction Types Synthesis: A + B AB Decomposition: AB A + B
Combustion:ALWAYS HAS O2 AS AREACTANT! AB + O AO + BO Reaction Types Single-Replacement (single-displacement): AX + B A + BX
Double-Replacement (double-displacement): AX + BY AY + BX