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Ch 2 - Elements + The Periodic Table

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!.

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Ch 2 - Elements + The Periodic Table

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  1. Ch 2 - Elements + The Periodic Table

  2. Chemical Symbols • Always start with: • Can be ___ or _____ letters

  3. Periodic Table:color code your table!

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

  5. READING the TABLE • Atomic # Tells us: Atomic Mass Tells us: Therefore, The # of neutrons =

  6. Practice:

  7. Do the Atomic Structure Worksheet

  8. Chemical Formulas • tell you which elementsare present in a compound, and their amount • Each new element is denoted by a CAPITAL LETTER. • NaCl = sodium and chlorine • MgBr =magnesium and bromine

  9. The subscript(the small number slightly belowthe line) tells you how many atoms are present – that number only applies to the element at the immediate leftof the number.

  10. Ex. H2O = 2 hydrogen atoms 1 oxygen atom • CaCl2 = 1 calcium atom 2 chlorine atoms

  11. Coefficientsare large numbers written in front of the compound symbol. This tells you how many molecules of that compound you have.

  12. Ex. 5NaNO3= 5 Na atoms 5 N atoms 15 O atoms 4NH4ClO3 = 4 N 16H 4 Cl 12 O

  13. Brackets around a complex ion, with a number to the immediate rightof the brackets, tells you how many of that complex ions you have in the compound. That number applies to all elements insidethe bracket.

  14. Ex. (NH4)2SO4 = 2N, 8H, 1S, 4O • Ex. 4Ca3(PO4)2 = 4[3Ca 2P, 8O)] = 12 Ca, 8P, 32O

  15. 1 magnesium atom 2 nitrogen atoms 6 oxygen atoms • Mg(NO3)2 = • 3Ba3(PO4)2 = 9 Barium atoms 6 potassium atoms 24 oxygen atoms

  16. Do the Reading Chemical Formula Worksheet

  17. Study for Quiz! • Atomic Structure worksheet • Reading Chemical Formula Worksheet • Models of Molecules

  18. Drawing Bohr Diagrams of Atoms • The nucleus contains all the protonsand neutrons. • Consequently, all the mass is concentrated in the nucleus. The electrons are arranged in specific ORBITALS around the nucleus.

  19. Orbital Limits • There is a specific limit to howmany electrons an orbital (or shell) can hold. • Within the orbitals, the electrons like to spread themselves out.

  20. Why Spread out? • electrons carry negative charges • negative charges repel

  21. Electrons fill the orbitals in the following pattern: Orbital: 1st2nd3rd4th 2e-8e- 8e- 18e- Which of these diagrams is incorrect? What elements are A,B,C,and D

  22. Once an orbital is full, the electrons will start filling the next orbital. • The innermost orbital (#1) gets filled first.

  23. Example: Hydrogen • Atomic # = ______ • Atomic Mass = ______ • # protons = ______ • # neutrons = ______ • # electrons = ______ 1 1 1 0 1

  24. Example Lithium • Atomic # = ______ • Atomic Mass = ______ • # protons = ______ • # neutrons = ______ • # electrons = ______ 3 7 3 4 3

  25. Example: Chlorine 17 • Atomic # = ______ • Atomic Mass = ______ • # protons = ______ • # neutrons = ______ • # electrons = ______ Now do the worksheet: “Models of the elements” 36 17 19 17

  26. The Valence Shell • Definitions: • 1) Valence Shell: the outermost orbital (or shell) • 2) Valence Electrons: _electrons in the outside shell

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

  28. Atoms can: • - _gain valence electrons • - _lose valence electrons • - _share valence electrons

  29. Example: Oxygen • Atomic # = _8____ • Mass = ___16___ • #p = _8___ • #e = _8___ • #n = _8___

  30. 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-___

  31. Will an Atom Gain or Lose Electrons? • Valence electronsGain/Lose? • greater than 4 gain • less than 4 lose • equal to 4 gain or lose

  32. exception: HYDROGEN • This element is unique because it has the ability to either gain or lose one electron to “fill” its orbitals.

  33. 7 14 • 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-

  34. When nitrogen is charged it is called _nitride

  35. 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!)

  36. 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!

  37. When naming NON-METAL ions, _change__ the name _ending_ to “_ide___” • e.g. _oxygen___ = __oxide_______ • __fluorine___ = _fluoride

  38. Non-metals form _negative ions. • (_#e- > #p+) • Metals form _positive_ ions. • (_#e- < #p+)

  39. Study for Bohr Diagrams Quiz!

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