1. Chemeketa Community College
Chapter 3:
Atoms & Elements
Larry Emme
Chemeketa Community College

2. Mixtures & Pure Substances Electron Energy Levels
Chapter Outline
Mixtures & Pure Substances
Elements & Symbols
The Periodic Table
Atomic Structure
Isotopes
Electron Energy Levels

3. Matter Weight on earth. The stuff things are made of.
Has Mass and takes up space.
(Air, water, rocks, etc..)
The amount of stuff (in g’s)
(Bowling Ball > Balloon)
Matter: The stuff things are made of. Has Mass and takes up space.
Mass: The amount of stuff. Usually measured in grams. Bowling ball has more mass than
Weight on earth.
Weight on earth.
Pull of Gravity on matter.

4. Classification of matter
Pure Substance
Mixture
Element
Compound Fe
FeS
Fe + S Mg
MgO
Mg + O2

5. Mixtures Air Pizza Urine Gasoline Tea w/ice Sand Mixture Homogeneous
(Solution)
Heterogeneous
Non-uniform composition
Uniform composition
Pizza
Gasoline
Tea w/ice
Air
Fe + S
Urine
Sand

6. American Periodic Table

7. Atomic Symbols Each element is assigned a unique symbol
Nitrogen
Hydrogen
Nickel
Aluminum
Bromine
Each element is assigned a unique symbol
1-2 letters; 1st is capitalized

8. Atomic Symbols
Some of the elements whose symbols are derived from other languages
Copper (Cuprum) Cu
Gold (Aurum) Au
Iron (Ferrum) Fe
Lead (Plumbum) Pb
Mercury (Hydrargyrum) Hg
Potassium (Kalium) K
Silver (Argentum) Ag
Sodium (Natrium) Na
Tin (Stannum) Sn
Tungsten (Wolfram) W

9. Atomic Symbols
Carbon
Copper (Cu)
Calcium
Cobalt
Chlorine
Chromium
Elements with same starting letter, get second letter added to the symbol

10. Periodic Table: Groups (Families)
Alkali Metals (exclude H)
Noble (Inert) gases
Alkaline Earth Metals
Halogens
I A
VIIIA H He
II A
III A IV A V A VI A VIIA Li Be B C N O F Ne
Transition Metals Na Mg Al Si P S Cl Ar
III B IVB V B VIB VIIB VIII B IB IIB K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Gd Cm Tb Bk Sm Pu Eu Am Nd U Pm Np Ce Th Pr Pa Yb No Lu Lr Er Fm Tm Md Dy Cf Ho Es

11. Periodic Table: Periods
Periods are
assigned numbers H He 1 2 3 4 5 6 7 Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

12. Metals Lustrous, malleable and ductile.
Conductors (heat & electricity)
Solids at room temp (except Hg)
Lose electrons to non-metals. H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

13. Non-metals Gas, liquid, solid (dull, brittle)H He Li Be At Te As Si B C N O F Ne Na Mg Al P S Cl Ar
Gas, liquid, solid (dull, brittle)
Poor conductors = Insulators
Many are diatomic molecules.
Gain e’s from metals
Share e’s with other non-metals K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

14. Metalloids Intermediate properties Semi conductors H He Li Be B C N OF Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Intermediate properties
Semi conductors Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

15. Metals Non-metals Metalloids H He Li Be B C N O F Ne Na Mg Al Si P SCl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

16. Atom - The smallest unit of an element that is still that element.
A model of matter
Atom - The smallest unit of an element that is still that element.
ie. Aluminum (Al)
Molecule -The smallest unit of a pure substance that is still that substance.
May contain > 1 atom or element.
ie. Water (H2O)

17. protons Structure of the atom & neutrons Nucleus =
Small, dense, + charge in the center of an atom. +
contains
protons + + + + +
&
neutrons

18. - charged particles that surround the nucleus.
Structure of the atom
Nucleus
Electrons
- charged particles that surround the nucleus.
Electrons move around the nucleus in orbits (orbitals).

19. Structure of the atom The nucleus is a small part of an atom.
If the nucleus was the size
of a marble, the atom would
fill a football stadium.
The nucleus would weigh
over 10,000 tons.

20. X - - - - - - The atomic symbol A = Mass number (amu)
= # protons + # neutrons - - X A - - Z + +
Z = Atomic number
= # protons
= # electrons (if neutral) - + + + + -

21. X - - - - - - 6 The atomic symbol A = Mass number 12 Z = Atomic number
= # protons + # neutrons 6 - - 6 X 12 - - 6 + +
Z = Atomic number
= # protons
= # electrons (if neutral) - + + + + -

22. C - - - - - - 6 The atomic symbol A = Mass number 12 Z = Atomic number
= # protons + # neutrons - - C 12 - - 6 + +
Z = Atomic number
= # protons
= # electrons (if neutral) - + + + + -

23. Na Sodium The atomic symbol A = Mass # = p + n = 23 23 11
Z = Atomic # = p = 11
Sodium

24. Why is the atomic weight on the tables not a whole #?47
Atomic number
Name of the element
Elemental Symbol
Silver Ag
107.87
Atomic mass (weight)
Atomic weight = The average, relative mass of an atom in an element.

25. - - - Isotopes of Hydrogen H H H + + +
Isotopes = Atoms of the same element but having different masses. 1 2 1 3 1 H H H - - - + + +
Protium
99.99%
Tritium
Trace %
Deuterium
0.01%

26. Average Atomic weight of Hydrogen
Isotopes of Hydrogen
Isotopes = Atoms of the same element but having different masses. 1 2 1 3 1 H H H - - - + + +
H-1 or Hydrogen-1
H-2 or Hydrogen-2
H-3 or Hydrogen-3
Average Atomic weight of Hydrogen
= amu

27. Average Atomic weight of C= 12.011 amu
Isotopes of Carbon
C-12 or Carbon-12
C-13 or Carbon-13
C-14 or Carbon-14 12 13 14 C C C 6 6 6 - - - - - - - - + + + - + + + + + + + + + - - + + + + + + - - - - - - -
98.89%
1.11%
Trace %
Average Atomic weight of C= amu

28. So falls apart (decays) Giving radioactive particles
Radioactive Isotopes 14 3 1 C H 6 - - - - + + + + + - + + - -
Nucleus is unstable
So falls apart (decays)
Giving radioactive particles

29. The atomic symbol & isotopes
Determine the number of protons, neutrons and electrons in each of the following.
15p,16n, 15e
56p,82n, 56e
92p,146n, 92e 31 15
138 56
238 92 P Ba U 24 12 19 9
Mg+2
F-1
12p,12n, 10e
9p,10n, 10e

30. Atomic Structure ____ ____ ____ 4 5 ___ Be 4 9 4 17 17 20 17
Symbol At# Mass P N e–
____ ____ ____ ___ Be
Cl ____ ___ ___ ___
Si ____ ____ ___ ___

31. fill layers around nucleus
Electron arrangement 24 12 Mg
Electrons
fill layers around nucleus
Low  High 32 18
A new layer is
added for each row or period in the table. 8 2
Shells = Energy levels

32. IA
IIA 1 H 4 2 He 7 3 Li 9 4 Be

33. IA
IIA
IIIA 1 H 11 5 B 7 3 Li 9 4 Be

34. IIIA
IVA VA 11 5 B 12 6 C 13 7 N

35. H He Be Li Ne Mg Ar Na 1 4 2 9 4 7 3 IA IIA VIIIA 20 10 23 11 24 40 1218 Ar 23 11 Na

36. H Be Li B Mg Al Na 1 9 7 4 3 1 Valence electrons Where most chemical
Reactions occur. 1 H 2 3 9 4 Be 7 3 Li 11 5 B 24 12 Mg 27 13 Al 23 11 Na
Inner electrons: No reactions if normal conditions.

37. Inner vs. valence electrons
This is where
most chemical
reactions
occur.
Inner electrons
Not much happens
here under normal
conditions.
With added energy inner electrons jump to
higher levels, then fall back giving E

38. 1 8 1 H 4 2 He 2 9 4 Be 20 10 Ne 7 3 Li 24 12 Mg 40 18 Ar 23 11 Na

39. H Li Na K H Li Lewis Structures Show only Valence Electrons Na 1 7 323 11 Na K

40. The End

41. End of Chapter Learning Checks Try these after you have reviewed the chapter

42. Learning Check
The element potassium is in the first group on the Periodic Table (group IA). Potassium is a. an alkali metal b. an alkaline earth metal c. a transition element d. a halogen

43. Learning Check Answers
The element potassium is in the first group on the Periodic Table (group IA). Potassium is a. an alkali metal b. an alkaline earth metal c. a transition element d. a halogen

44. Learning Check
The elements on the periodic table are placed in order of increasing
Density
Atomic number
Boiling point
Atomic mass

45. Learning Check Answers
The elements on the periodic table are placed in order of increasing
Density
Atomic number
Boiling point
Atomic mass

46. Learning Check
A solid sample of an unknown element is dull and brittle and does not conduct heat or electricity. How should the element be classified?
Metal
Nonmetal
Metalloid
Transition element

47. Learning Check
A solid sample of an unknown element is dull and brittle and does not conduct heat or electricity. How should the element be classified?
Metal
Nonmetal
Metalloid
Transition element

48. Learning Check The majority of the elements are Metals Gases Nonmetals
Metalloids

49. Learning Check Answers
The majority of the elements are
Metals
Gases
Nonmetals
Metalloids

50. Learning Check Which is not a metalloid? Boron (B) Silicon (Si)
Germanium (Ge)
Aluminum (Al)

51. Learning Check Answers
Which is not a metalloid?
Boron (B)
Silicon (Si)
Germanium (Ge)
Aluminum (Al)

52. Learning Check Which of the following is not a diatomic element?
Fluorine
Oxygen
Nitrogen
Carbon

53. Learning Check Answers
Which of the following is not a diatomic element?
Fluorine
Oxygen
Nitrogen
Carbon

54. Learning Check Which of the following nonmetals is not reactive?
Helium
Fluorine
Oxygen
Carbon

55. Learning Check Answers
Which of the following nonmetals is not reactive?
Helium
Fluorine
Oxygen
Carbon