Naming Anions (know table 2.6 pg 55)Names and Formulas of Ionic CompoundsHydrated Ionic CompoundsChapter 2 – Atoms and MoleculesAtomic Structure and Mass Subatomic Particle Abbreviation Mass (kg) Mass (amu) Charge Proton P, H+1.67262x10-27~ 1+1.609x10-19(+1)Neutron N 1.67492x10-27~ 1 0Electron e-9.109x10-31~ 1/200th-1.609x10-19 1.)Atom: Always neutral because number of protons is equal to number of electrons2.) Ion: a charged particle, atom, element, or molecule (number of protons DOES NOT equal number of electrons)3.)Cation: a positively charged ion 4.)Anion: a negatively charged ion5.)Atomic number: equal to the number of protons and defines the element (symbolized by Z)6.)Mass number: equal to the number of protons plus neutrons (symbolized by A)7.)Isotopes: atoms of same element that differ only by number of neutrons Examples:12C13C14C23Na+ 31P3-Protons 6 6 6 11 15Neutrons 6 7 8 12 16Electrons 6 6 6 10 18Atomic Masses: weighted average of the natural occurring isotopes. Referred to as atomic weight, average atomic mass, and also molar massExample: Isotope mass (amu) abundance 24Mg 23.9850 78.99% 25Mg 24.9858 10.00%26Mg 25.9826 11.01% Compounds and Chemical Bonds - Chemical compound: 2 or more elements held together by chemical forces- Chemical Formula: shows the number and types of atoms1. Molecular formula: exact number of elements (C3H6)2. Empirical formula: relative number of each element (CH2)- Chemical Bonds: involve the exchange or sharing of electrons. Elements do this to become more stable.- Three types1. Ionic: metals lose an electron to become a cation and nonmetals gain an electron to become anion2. Metallic: sea of electrons with delocalized sharing (occurs with metals)3. Covalent: typically between 2 nonmetals sharing electrons The Periodic Table: elements grouped in given vertical column share similar chemical and physical propertiesChemical Nomenclature In order to correctly name a compound, you must first determine if the compound is ionic or molecular. Molecular Compounds: 2 nonmetal binary elements that form a covalent bond (use number prefixes) Ionic Compounds: one metal and one nonmetal binary compound that forms ionic bonds (don’t use prefixes) Important: Metals tend to lose electrons and become cations. Nonmetals tend to gain electrons and become anions. Naming Cations ( Know Table 2.5 pg 55) 1. Monatomic Cations from the Main Groups – the name is the same as the name of the element Na _Sodium___ Na+ _Sodium____ Charge of Group 1 __+1___ Ca _Calcium___ Ca2+ _Calcium___ Charge of Group 2 _+2____ Al _Aluminum__ Al3+ _Aluminum_ Charge of Aluminum __+3__ In addition to Groups 1, 2, and Aluminum, you should know the charge of the silver ion and the zinc ion: Ag+ and Zn2+2. Some transition metals form more than one cation: Two ways to name: Fe2+ _ferrous______ or _iron (II)____ Fe3+ _ferric_______ or _iron (III)____ Cu+ _cuprous_____ or _copper (I)___ Cu2+ _cupric______ or _copper (II)___ 3. Know two polyatomic cations: Ammonium __NH4___ (easy to remember because the formula for ammonia is _NH3__)Hydronium _H3O + ___ Naming Anions (know table 2.6 pg 55) 1. Monoatomic Anions – change the element ending to “-ide” Cl _chlorine____ Cl– _chloride____ Charge of Group 17 anions: _-1______ O _oxygen_____ O2– _oxide______ Charge of Group 16 anions: _-2_______ N _nitrogen____ N3– _nitrite______ Charge of Group 15 anions: _-3_______ 2. two polyatomic anions ending in “-ide”: hydroxide __OH - ________ cyanide __CN - ________ 3. Eight important oxoanions: acetate C2H3O2- _or_CH3COO - _ permanganate __MnO42- _____ carbonate __CO32- _________ phosphate __PO43- _______ chlorate __ClO3- _________ sulfate __SO42- _______ nitrate __NO3- _________ chromate __CrO42- ______ 4. If you memorize nitrate and sulfate, then you also know nitrite and sulfite. (One less oxygen, but the same charge.) sulfate __SO42- _________ sulfite __SO32- _________ nitrate __NO3- _________ nitrite __NO2- _________ 5. If you memorize chlorate, then you know 12 polyatomic anions in all: ClO4– _perchlorate__ _BRO4______ _perbromate_ _IO4- _______ _periodate___ ClO3– _chlorate_____ _BRO3- ______ _bromate____ _IO3- _______ _iodate_____ ClO2– _chlorite_____ _BRO2- ______ _bromite____ _IO2- ______ _iodite______ClO– _hypochlorite__ _BRO - _______ _hypobromite_ _IO - _______ _hypoidite____ Names and Formulas of Ionic Compounds Two important principles: 1. To name an ionic compound, name the _cation_ and then name the _anion_. Do not use _number prefixes__ such as _di, tri, tetra______. For example, MgCl2 is _magnesium chloride___ not __magnesium dichloride_____. 2. The overall formula for an ionic compound must be __electronically neutral______. That is, the number of positive charges __must equal_ the number of negative charges. Only use parentheses if you have _more than one___ of a __polyatomic ion___. Examples: Give the formulas of the following ionic compounds: magnesium chloride __MgCl2____ sodium nitrate __NaNO3____ iron(III) bromide __FeBr3_____ calcium hydroxide __Ca(OH)2____ magnesium sulfide __MgS______ Hydrated Ionic Compounds Some ionic compounds, called __hydrates__, contain a specific number of __water molecules__ associated with each __formula unit___. Know the common hydrate prefixes: # of water molecules prefix # of water molecules prefix ½ _hemi_____ 1 _mono_____ 5 _penta_____ 2 _di_______ 6 _hexa_____ 3 _tri_______ 7 _hepta_____4 _tetra_____ 8 _octa______ CoCl2 · 6 H2O _cobalt (II) chloride hexahydrate__ BeCl2 · 2 H2O _beryllium chloride dihydrate___ Cobalt (II) phosphate octahydrate _CO3(PO -1)_x_8H2O_ magnesium bromite hexahydrate __Mg(BRO2)2_x