1. Atoms and the periodic table
Pre-chem ch. 3
Atoms and the periodic table

2. Pre-chem ch. 3 Lo Describe the emergence of the Periodic Table
Determine an elements: protons, neutrons, electrons, family, period, atomic mass, atomic number.
Describe patterns on the Periodic Table, including relationship between electrons and group characteristics
Determine a Determine an elements electron energy level
Convert between moles and mass

3. Atoms
Every element is made of tiny, unique particles called atoms that cannot be subdivided
Atoms of the same element are exactly alike
Atoms of different elements can join to form molecules

4. Variations on the atom
Aristotle
Democritus
Dalton
Bohr

5. Electrons
Energy levels- e- can only be in certain E levels, they must gain E to move to a higher level or lose E to move to a lower E level
Valence electrons

6. What an atom consists of

7. Periodic table key

8. Determining the make up of an element
Protons (p+)
Electrons (e-)
Neutrons (n)
Atomic mass
Atomic number C 6
(12.01) 12 Mg O Zn Fe

9. Atom vs. ion Atom Ion P+ and e – are equal Atomic number = #p+
No charge
Neutrons plus protons= atomic mass
P+ and e – are NOT equal
Atomic number = #p+
Charge
Cation
Anion
Neutrons plus protons= atomic mass

10. How to figure out electrons in an ion
Charge= protons- electrons
-2= 10 protons – X electrons
X = 12 electrons
+3 = 10 protons – X electrons
X= 7 electrons

11. Atom or ion practice Element Atom/ion A Mass A# p+ e- n O2- Ion 16 810
Mg+2
Na+ Na
Fe+3

12. isotope Hydrogen Isotopes Protium Deutrium Tritium Carbon 12, 13, 14
Nitrogen 12, 14

13. Perioidc table lay out

14. QR code to Periodic table.. No way!
Open and scan each element to hear a short video on it, courtesy of University of Nottingham
QR code periodic table

15. Families of elements

16. Potassium, K reacts with water and must be stored in kerosene
Alkali Metals (group 1)
All alkali metals have 1 valence electron
Alkali metals are NEVER found pure in nature; they are too reactive
Reactivity of these elements increases down the group
Group info from sciencegeek.net
Potassium, K reacts with water and must be stored in kerosene

17. Alkaline Earth Metals (group 2)
All alkaline earth metals have 2 valence electrons
Alkaline earth metals are less reactive than alkali metals
Alkaline earth metals are not found pure in nature; they are too reactive
The word “alkaline” means “basic”
common bases include salts of the metals
Ca(OH)2
Mg(OH)2

18. Properties of Metals
Metals are good conductors of heat and electricity
Metals are malleable
Metals are ductile
Metals have luster

19. Transition Metals
Copper, Cu, is a relatively soft metal, and a very good electrical conductor.
Mercury, Hg, is the only metal that exists as a liquid at room temperature

20. Properties of Metalloids
They have properties of both metals and nonmetals.
Metalloids are more brittle than metals, less brittle than most nonmetallic solids
Metalloids are semiconductors of electricity
Some metalloids possess metallic luster

21. Silicon, Si – A Metalloid
Silicon has metallic luster
Silicon is brittle like a nonmetal
Silicon is a semiconductor of electricity
Other metalloids include:
Boron, B
Germanium, Ge
Arsenic, As
Antimony, Sb
Tellurium, Te

22. Nonmetals Nonmetals are poor conductors of heat and electricity
Nonmetals tend to be brittle
Many nonmetals are gases at room temperature
Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element.

23. Examples of Nonmetals
Microspheres of phosphorus, P, a reactive nonmetal
Sulfur, S, was once known as “brimstone”
Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

24. Halogens Halogens all have 7 valence electrons
Halogens are never found pure in nature; they are too reactive
Halogens in their pure form are diatomic molecules (F2, Cl2, Br2, and I2)
Chlorine is a yellow-green poisonous gas

25. Noble Gases
Noble gases have 8 valence electrons (except helium, which has only 2)
Noble gases are ONLY found pure in nature – they are chemically unreactive
Colorless, odorless and unreactive; they were among the last of the natural elements to be discovered

26. Electron Energy Levels

27. orbital

28. P orbital

29. D orbital

30. F orbital

31. Electron config examplesH B O Mg N Fe Zn

33. Noble gas config (shorthand)
Use the noble gas before your element, put it in [brackets]
Mg example: [Ne]
Subtract that many e- from your total
12-10= 2
Keep going up until you have used all your e-
3s2
Answer
Mg= [Ne] 3s2

34. Noble gas config examplesMg N Fe Zn

36. Using Moles Avagadro’s number Molar mass= 1 mole
6.022 x 1023 is a mole of a substance (gumballs, H, He, etc)
Molar mass= 1 mole

37. Conversion ex. With molar mass
Fe= 5.50 mol Fe
mm= g/mol Fe
Mass of Fe?
5.50 mol Fe g Fe 307 g Fe
1 mol Fe

38. More….
2.50 mol S is how many g S?
0.50 mol C is how many g C?

39. 352 g Fe is how many mol Fe?
620 g Hg is how many mol Hg?
11g Si is how many mol Si?