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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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Presentation on theme: "Ch 2 - Elements + The Periodic Table Chemical Symbols  Always start with:  Can be ___ or _____ letters  Always start with:  Can be ___ or _____ letters."— Presentation transcript:

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2 Ch 2 - Elements + The Periodic Table

3 Chemical Symbols  Always start with:  Can be ___ or _____ letters  Always start with:  Can be ___ or _____ letters

4 Periodic Table:color code your table!

5 Metals, Non-metals, Metalloids  Fill in the graphic organizer to record the basic properties of groupings on the periodic table!

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 =

7 Practice:

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 Gold 11 Pb

9 Name of ElementSymbolAtomic Number Atomic Mass Number of Protons Number of Electron Number of Neutrons PotassiumK BromineBr AluminumAl LithiumLi37334 Magnesiu m Mg OxygenO NickelNi NeonNe ArgonAr GoldAu SodiumNa LeadPb

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

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.

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

13  Coefficients are large numbers written in front of the compound symbol. This tells you how many molecules of that compound you have.

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

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.

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

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

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

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

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

21 Study for Quiz!  Atomic Structure worksheet  Reading Chemical Formula Worksheet  Models of Molecules  Atomic Structure worksheet  Reading Chemical Formula Worksheet  Models of Molecules

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.

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.

24 Why Spread out?  electrons carry negative charges  negative charges repel  electrons carry negative charges  negative charges repel

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

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.

27 Example: Hydrogen  Atomic # = ______  Atomic Mass = ______  # protons =______  # neutrons = ______  # electrons = ______  Atomic # = ______  Atomic Mass = ______  # protons =______  # neutrons = ______  # electrons = ______

28 Example Lithium  Atomic # = ______  Atomic Mass = ______  # protons =______  # neutrons = ______  # electrons = ______  Atomic # = ______  Atomic Mass = ______  # protons =______  # neutrons = ______  # electrons = ______

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”

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

31  The Valence Electrons are involved in forming bonds with other atoms. The inner electrons and nucleus are not involved in bonding.

32  Atoms can:  - _gain valence electrons  - _lose valence electrons  - _share valence electrons  Atoms can:  - _gain valence electrons  - _lose valence electrons  - _share valence electrons

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___

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 - ___

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

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.

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 ? __

38  When nitrogen is charged it is called _nitride

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!)

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!_.

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

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+)

43 Study for Bohr Diagrams Quiz!


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