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Ch 2 - Elements + The Periodic Table Chemical Symbols Always start with: Can be ___ or _____ letters Always start with: Can be ___ or _____ letters

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Slide 2 Ch 2 - Elements + The Periodic Table Slide 3 Chemical Symbols Always start with: Can be ___ or _____ letters Always start with: Can be ___ or _____ letters Slide 4 Periodic Table:color code your table! Slide 5 Metals, Non-metals, Metalloids Fill in the graphic organizer to record the basic properties of groupings on the periodic table! Slide 6 READING the TABLE Atomic # Tells us: Atomic Mass Tells us: Therefore, The # of neutrons = Atomic # Tells us: Atomic Mass Tells us: Therefore, The # of neutrons = Slide 7 Practice: Slide 8 Do the Atomic Structure Worksheet Name of Element Symbol of Element Atomic Number Atomic Mass Number of Protons Number of Electrons Number of Neutrons K 35 Al Li 12 8 Ni 10 18 Gold 11 Pb Slide 9 Name of ElementSymbolAtomic Number Atomic Mass Number of Protons Number of Electron Number of Neutrons PotassiumK193919 20 BromineBr358035 45 AluminumAl132713 14 LithiumLi37334 Magnesiu m Mg122412 OxygenO816888 NickelNi285928 31 NeonNe102010 ArgonAr184018 22 GoldAu7919779 118 SodiumNa112311 12 LeadPb8220782 125 Slide 10 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 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 Slide 11 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. Slide 12 Ex. H 2 O = 2 hydrogen atoms 1 oxygen atom CaCl 2 = 1 calcium atom 2 chlorine atoms Ex. H 2 O = 2 hydrogen atoms 1 oxygen atom CaCl 2 = 1 calcium atom 2 chlorine atoms Slide 13 Coefficients are large numbers written in front of the compound symbol. This tells you how many molecules of that compound you have. Slide 14 Ex. 5NaNO 3 = 5 Na atoms 5 N atoms 15 O atoms 4NH 4 ClO 3 = 4 N 16H 4 Cl 12 O Ex. 5NaNO 3 = 5 Na atoms 5 N atoms 15 O atoms 4NH 4 ClO 3 = 4 N 16H 4 Cl 12 O Slide 15 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. Slide 16 Ex. (NH 4 ) 2 SO 4 = 2N, 8H, 1S, 4O Ex. 4Ca 3 (PO 4 ) 2 = 4[3Ca 2P, 8O)] = 12 Ca, 8P, 32O Ex. (NH 4 ) 2 SO 4 = 2N, 8H, 1S, 4O Ex. 4Ca 3 (PO 4 ) 2 = 4[3Ca 2P, 8O)] = 12 Ca, 8P, 32O Slide 17 Mg(NO 3 ) 2 = 3Ba 3 (PO 4 ) 2 = Mg(NO 3 ) 2 = 3Ba 3 (PO 4 ) 2 = 1 magnesium atom 2 nitrogen atoms 6 oxygen atoms 9 Barium atoms 6 potassium atoms 24 oxygen atoms Slide 18 Do the Reading Chemical Formula Worksheet 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 Ex. 2NaCl 2Sodium Chlorine 2 sodium 2chlorine 42 3N 2 O 3 2KHCO 3 5FeSO 3 C 6 H 12 O 6 3K 2 Cr 2 O 7 CH 3 COOH Mg(OH) 2 3 Al(OH) 3 4CuClO 3 Slide 19 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 Ex. 2NaCl 2Sodium Chlorine 2 sodium 2chlorine 42 3N 2 O 3 2Nitrogen Oxygen 6 N 9O 153 2KHCO 3 4Potassium Hydrogen Carbon Oxygen 2 Potassium 2 Hydrogen 2 Carbon 6 Oxygen 122 5FeSO 3 3Iron Sulphur Oxygen 5 Iron 5 Sulphur 15 Oxygen 255 C 6 H 12 O 6 3Carbon Hydrogen Oxygen 6 Carbon 12 Hydrogen 6 Oxide 241 Slide 20 Chemical Formula Number of Different Types of Atoms Names of Each atom presentNumber of each type of atom Total Number of Atoms present Number of molecules of this compound 3K 2 Cr 2 O 7 3Potassium Chromium Oxygen 6 Potassium 6 Chromium 21 Oxygen 333 CH 3 COOH 3Carbon Hydrogen Oxygen 2 Carbon 4 Hydrogen 2 Oxygen 81 Mg(OH) 2 3Magnesium Oxygen Hydrogen 1 Magnesium 2 Hydrogen 2 Oxygen 51 3 Al(OH) 3 3Aluminum Oxygen Hydrogen 3 Aluminum 9 Oxygen 9 Hydrogen 213 4CuClO 3 3Copper Chloride Oxygen 4 Copper 4 Chloride 12 Oxygen 204 Slide 21 Study for Quiz! Atomic Structure worksheet Reading Chemical Formula Worksheet Models of Molecules Atomic Structure worksheet Reading Chemical Formula Worksheet Models of Molecules Slide 22 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. 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. Slide 23 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. 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. Slide 24 Why Spread out? electrons carry negative charges negative charges repel electrons carry negative charges negative charges repel Slide 25 Electrons fill the orbitals in the following pattern: Orbital: 1 st 2 nd 3 rd 4 th 2e - 8e - 8e - 18e - Electrons fill the orbitals in the following pattern: Orbital: 1 st 2 nd 3 rd 4 th 2e - 8e - 8e - 18e - Which of these diagrams is incorrect? What elements are A,B,C,and D Slide 26 Once an orbital is full, the electrons will start filling the next orbital. The innermost orbital (#1) gets filled first. Once an orbital is full, the electrons will start filling the next orbital. The innermost orbital (#1) gets filled first. Slide 27 Example: Hydrogen Atomic # = ______ Atomic Mass = ______ # protons =______ # neutrons = ______ # electrons = ______ Atomic # = ______ Atomic Mass = ______ # protons =______ # neutrons = ______ # electrons = ______ 1 1 1 0 1 Slide 28 Example Lithium Atomic # = ______ Atomic Mass = ______ # protons =______ # neutrons = ______ # electrons = ______ Atomic # = ______ Atomic Mass = ______ # protons =______ # neutrons = ______ # electrons = ______ 3 7 3 4 3 Slide 29 Example: Chlorine Atomic # = ______ Atomic Mass = ______ # protons =______ # neutrons = ______ # electrons = ______ Now do the worksheet: Models of the elements Atomic # = ______ Atomic Mass = ______ # protons =______ # neutrons = ______ # electrons = ______ Now do the worksheet: Models of the elements 17 36 17 19 17 Slide 30 The Valence Shell Definitions: 1) Valence Shell: the outermost orbital (or shell) 2) Valence Electrons: _electrons in the outside shell Definitions: 1) Valence Shell: the outermost orbital (or shell) 2) Valence Electrons: _electrons in the outside shell Slide 31 The Valence Electrons are involved in forming bonds with other atoms. The inner electrons and nucleus are not involved in bonding. Slide 32 Atoms can: - _gain valence electrons - _lose valence electrons - _share valence electrons Atoms can: - _gain valence electrons - _lose valence electrons - _share valence electrons Slide 33 Example: Oxygen Atomic # = _8____ Mass = ___16___ #p = _8___ #e = _8___ #n = _8___ Example: Oxygen Atomic # = _8____ Mass = ___16___ #p = _8___ #e = _8___ #n = _8___ Slide 34 Combining Capacity: The number of electrons that an atom must gain or lose to have a full valence shell. Full for 1 st shell = _2e - ___ Full for 2 nd shell = _8e - ___ Full for 3 rd shell = _8e - ___ Combining Capacity: The number of electrons that an atom must gain or lose to have a full valence shell. Full for 1 st shell = _2e - ___ Full for 2 nd shell = _8e - ___ Full for 3 rd shell = _8e - ___ Slide 35 Will an Atom Gain or Lose Electrons? Valence electronsGain/Lose? greater than 4 gain less than 4lose equal to 4gain or los e Will an Atom Gain or Lose Electrons? Valence electronsGain/Lose? greater than 4 gain less than 4lose equal to 4gain or los e Slide 36 exception: HYDROGEN This element is unique because it has the ability to either gain or lose one electron to fill its orbitals. exception: HYDROGEN This element is unique because it has the ability to either gain or lose one electron to fill its orbitals. Slide 37 Examples: Nitrogen atomic # = _____ 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- Examples: Nitrogen atomic # = _____ 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- 7 14 Slide 38 When nitrogen is charged it is called _nitride Slide 39 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!) 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!) Slide 40 Now go back and answer the questions on the Bohr diagram worksheets! Charge: Atoms are neutral if #p+ = # e- If atoms gain or lose electrons they become _charged = IONS!_. Charge: Atoms are neutral if #p+ = # e- If atoms gain or lose electrons they become _charged = IONS!_. Slide 41 When naming NON-METAL ions, _change__ the name _ending_ to _ide___ e.g. _oxygen___ = __oxide_______ __fluorine___ = _fluoride When naming NON-METAL ions, _change__ the name _ending_ to _ide___ e.g. _oxygen___ = __oxide_______ __fluorine___ = _fluoride Slide 42 Non-metals form _negative ions. (_#e- > #p+) Metals form _positive_ ions. (_#e- < #p+) Non-metals form _negative ions. (_#e- > #p+) Metals form _positive_ ions. (_#e- < #p+) Slide 43 Study for Bohr Diagrams Quiz!