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 Therefore, The # of
neutrons =

6. Practice:

7. 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

8. Potassium K 19 39 20 Bromine Br 35 80 45 Aluminum Al 13 27 14 Lithium
Name of Element
Symbol
Atomic Number
Atomic Mass
Number of Protons
Number of Electron
Number of Neutrons
Potassium K 19 39 20
Bromine Br 35 80 45
Aluminum Al 13 27 14
Lithium Li 3 7 4
Magnesium Mg 12 24
Oxygen O 8 16
Nickel Ni 28 59 31
Neon Ne 10
Argon Ar 18 40 22
Gold Au 79
197
118
Sodium Na 11 23
Lead Pb 82
207
125

9. 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

10. 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.

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

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

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

14. 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.

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

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

17. Do the Reading Chemical Formula Worksheet
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 2
Sodium
Chlorine
2 sodium
2chlorine 4
3N2O3
2KHCO3
5FeSO3
C6H12O6
3K2Cr2O7
CH3COOH
Mg(OH)2
3 Al(OH)3
4CuClO3

18. Potassium Hydrogen Carbon Oxygen 2 Potassium 2 Hydrogen
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 2
Sodium
Chlorine
2 sodium
2chlorine 4
3N2O3
Nitrogen
Oxygen
6 N 9O 15 3
2KHCO3
Potassium Hydrogen Carbon Oxygen
2 Potassium 2 Hydrogen
2 Carbon 6 Oxygen 12
5FeSO3
Iron Sulphur Oxygen
5 Iron 5 Sulphur 15 Oxygen 25 5
C6H12O6
Carbon Hydrogen Oxygen
6 Carbon 12 Hydrogen 6 Oxide 24 1

19. Potassium Chromium Oxygen 6 Potassium 6 Chromium 21 Oxygen 33
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
3K2Cr2O7 3
Potassium Chromium Oxygen
6 Potassium 6 Chromium 21 Oxygen 33
CH3COOH
Carbon Hydrogen Oxygen
2 Carbon 4 Hydrogen 2 Oxygen 8 1
Mg(OH)2
Magnesium Oxygen Hydrogen
1 Magnesium 2 Hydrogen 2 Oxygen 5
3 Al(OH)3
Aluminum Oxygen Hydrogen
3 Aluminum 9 Oxygen 9 Hydrogen 21
4CuClO3
Copper Chloride Oxygen
4 Copper 4 Chloride 12 Oxygen 20 4

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

21. 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.

22. 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.

23. Why Spread out? electrons carry negative charges
negative charges repel

24. Electrons fill the orbitals in the following pattern:
Orbital: 1st 2nd 3rd 4th
2e- 8e- 8e- 18e-
Which of these diagrams is incorrect?
What elements are A,B,C,and D

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

26. Example: Hydrogen Atomic # = ______ Atomic Mass = ______
# protons = ______
# neutrons = ______
# electrons = ______ 1 1 1 1

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

28. Example: Chlorine Atomic # = ______ Atomic Mass = ______17
Atomic # = ______
Atomic Mass = ______
# protons = ______
# neutrons = ______
# electrons = ______
Now do the worksheet:
“Models of the elements” 36 17 19 17

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

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

31. Atoms can:
- _gain valence electrons
- _lose valence electrons
- _share valence electrons

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

33. 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-___

34. Will an Atom Gain or Lose Electrons? Valence electrons Gain/Lose?
greater than gain
less than 4 lose
equal to 4 gain or lose

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

36. 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

37. When nitrogen is charged it is called _nitride

38. 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!)

39. 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!_.
Now go back and answer the questions on the Bohr diagram worksheets!

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

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

42. Study for Bohr Diagrams Quiz!