Ch 2 - Elements + The Periodic Table Chemical Symbols Always start with: Can be ___ or _____ letters Periodic Table:color code your table! Metals, Non-metals, Metalloids Fill in the graphic organizer to record the basic properties of groupings on the periodic table! Metals Metalloids Properties: Non-metals Properties: Properties: STP state: STP state: STP state: Appearance: Appearance: Appearance: Conductiv ity : Conductiv ity : Conductiv ity : Malleability : Malleability : Malleability : Ductility : Ductility : Alkali metals: a.k.a. Group 1 Ductility : Halogens: a.k.a. Group 17 Elements: Elements: Key f eatures: Key f eatures: Common uses: Common uses: Other: Other: Alkaline earth metals: a.k.a. Group 2 Noble gases: a.k.a. Group 18 Elements: Elements: Key f eatures: Key f eatures: Common uses: Common uses: Other: Other: READING the TABLE Atomic # Tells us: Atomic Mass Tells us: Therefore, The # of neutrons = Practice: NEUTRAL Atoms of the Ele ments! Name Symbol Atomic Atomic # Mass Bromine Br 35 80 amu Manganese Mn 25 55amu Gold Au 79 197 Aluminum Al 13 27 Lead Pb 82 207 # of protons 35 25 79 13 82 # of electrons 35 25 79 13 82 # of neutr ons 45 30 118 14 125 Do the Atomic Structure Worksheet Name of Element Symbol of Element Atomic Number Atomic Mass Number of Protons Number of Electrons K 35 Al Li 12 8 Ni 10 18 Gold 11 Pb Number of Neutrons Name of Element Symbol Atomic Number Atomic Mass Number of Protons Number of Electron Number of Neutrons Potassium K 19 39 19 19 20 Bromine Br 35 80 35 35 45 Aluminum Al 13 27 13 13 14 Lithium Li 3 7 3 3 4 Magnesiu m Oxygen Mg 12 24 12 12 12 O 8 16 8 8 8 Nickel Ni 28 59 28 28 31 Neon Ne 10 20 10 10 10 Argon Ar 18 40 18 18 22 Gold Au 79 197 79 79 118 Sodium Na 11 23 11 11 12 Lead Pb 82 207 82 82 125 Chemical Formulas tell you which elements are present in a compound, and their amount Each new element is denoted by a CAPITAL LETTER. NaCl = sodium and chlorine MgBr =magnesium and bromine The subscript (the small number slightly below the line) tells you how many atoms are present – that number only applies to the element at the immediate left of the number. Ex. H2O = 2 hydrogen atoms 1 oxygen atom CaCl2 = 1 calcium atom 2 chlorine atoms Coefficients are large numbers written in front of the compound symbol. This tells you how many molecules of that compound you have. Ex. 5NaNO3 = 5 Na atoms 5 N atoms 15 O atoms 4NH4ClO3 = 4 N 16H 4 Cl 12 O Brackets around a complex ion, with a number to the immediate right of the brackets, tells you how many of that complex ions you have in the compound. That number applies to all elements inside the bracket. Ex. (NH4)2SO4 = 2N, 8H, 1S, 4O Ex. 4Ca3(PO4)2 = 4[3Ca 2P, 8O)] = 12 Ca, 8P, 32O Mg(NO3)2 = 1 magnesium atom 2 nitrogen atoms 6 oxygen atoms 3Ba3(PO4)2 = 9 Barium atoms 6 potassium atoms 24 oxygen atoms Do the Reading Chemical Formula Worksheet Chemical Formula Ex. 2NaCl 3N2O3 2KHCO3 5FeSO3 C6H12O6 3K2Cr2O7 CH3COOH Mg(OH)2 3 Al(OH)3 4CuClO3 Number of Different Types of Atoms 2 Names of Each atom present Number of each type of atom Sodium Chlorine 2 sodium 2chlorine Total Number Number of of Atoms molecules of present this compound 4 2 Chemical Formula Ex. 2NaCl Number of Different Types of Atoms 2 2 3N2O3 4 2KHCO3 3 5FeSO3 3 C6H12O6 Names of Each atom present Sodium Chlorine Nitrogen Oxygen Potassium Hydrogen Carbon Oxygen Number of each type of atom 2 sodium 2chlorine 6N 9O 2 Potassium 2 Hydrogen 2 Carbon 6 Oxygen Iron 5 Iron Sulphur 5 Sulphur Oxygen 15 Oxygen Carbon 6 Carbon Hydrogen 12 Oxygen Hydrogen 6 Oxide Total Number of Atoms present Number of molecules of this compound 4 2 15 3 12 2 25 5 24 1 Chemical Formula Number of Different Types of Atoms Names of Each atom present Number of each type of atom Total Number of Atoms present Number of molecules of this compound 3 Potassium Chromium Oxygen Carbon Hydrogen Oxygen Magnesium Oxygen Hydrogen Aluminum Oxygen Hydrogen 6 Potassium 6 Chromium 21 Oxygen 2 Carbon 4 Hydrogen 2 Oxygen 1 Magnesium 2 Hydrogen 2 Oxygen 3 Aluminum 9 Oxygen 9 Hydrogen 33 3 8 1 5 1 21 3 Copper Chloride Oxygen 4 Copper 4 Chloride 12 Oxygen 20 4 3K2Cr2O7 3 CH3COOH 3 Mg(OH)2 3 3 Al(OH)3 3 4CuClO3 Study for Quiz! Atomic Structure worksheet Reading Chemical Formula Worksheet Models of Molecules Drawing Bohr Diagrams of Atoms The nucleus contains all the protons and neutrons. Consequently, all the mass is concentrated in the nucleus. The electrons are arranged in specific ORBITALS around the nucleus. Orbital Limits There is a specific limit to how many electrons an orbital (or shell) can hold. Within the orbitals, the electrons like to spread themselves out. Why Spread out? electrons carry negative charges negative charges repel Electrons fill the orbitals in the following pattern: Orbital: 1st 4th 2e- 2nd 3rd 8e- 8e- Which of these diagrams is incorrect? What elements are A,B,C,and D 18e- Once an orbital is full, the electrons will start filling the next orbital. The innermost orbital (#1) gets filled first. Example: Hydrogen Atomic # = 1 ______ 1 Atomic Mass = ______ 1 # protons = ______ 0 # neutrons = ______ 1 # electrons = ______ Example Lithium Atomic # = 3 ______ Atomic Mass = ______ 7 # protons = ______ 3 4 # neutrons = ______ 3 # electrons = ______ Example: Chlorine 17 ______ 36 Atomic Mass = ______ 17 # protons = ______ 19 # neutrons = ______ 17 # electrons = ______ Atomic # = Now do the worksheet: “Models of the elements” Definitions: 1) Valence Shell: the outermost orbital (or shell) 2) Valence Electrons: _electrons in the outside shell The Valence Shell The Valence Electrons are involved in forming bonds with other atoms. The inner electrons and nucleus are not involved in bonding. Atoms can: - _gain valence electrons - _lose valence electrons - _share valence electrons Example: Oxygen Atomic # = _8____ Mass = ___16___ #p = _8___ #e = _8___ #n = _8___ Combining Capacity: The number of electrons that an atom must gain or lose to have a full valence shell. Full for 1st shell = _2e-___ Full for 2nd shell = _8e-___ Full for 3rd shell = _8e-___ Will an Atom Gain or Lose Electrons? Valence electrons greater than 4 less than 4 equal to 4 Gain/Lose? gain lose gain or lose exception: HYDROGEN This element is unique because it has the ability to either gain or lose one electron to “fill” its orbitals. Examples: Nitrogen 7 atomic # = _____ 14 mass = _____ #p = _7____ #n = _7____ #e = _7____ # valence e = _5____ Will this atom gain or lose? __gain_ How many ? ___3____ What is its combining capacity? _3-_ Charge ? __3- When nitrogen is charged it is called _nitride Example 2: Neon atomic # = _10____ mass = ___20__ #p = __10___ #n = __10___ #e = __10___ # valence e = __8___ Will this atom gain or lose? __neither___ How many ? ___0____ What is its combining capacity? _0_____ Charge ? __0____ Atoms with C.C. =_0=_INERT (NOBLE)_ that is , they will not blow up! (or react at all!) Charge: Atoms are neutral if #p+ = # e If atoms gain or lose electrons they become _charged = IONS!_. Now go back and answer the questions on the Bohr diagram worksheets! When naming NON-METAL ions, _change__ the name _ending_ to “_ide___” e.g. _oxygen___ = __oxide_______ __fluorine___ = _fluoride Non-metals form _negative ions. (_#e- > #p+) Metals form _positive_ ions. (_#e- < #p+) Study for Bohr Diagrams Quiz!