1. The Periodic Table and Atomic Structure
Section 2.1

2. Review Last class? Four classical atomic models
Quantum Mechanical Model

3. Objectives
Distinguish between metals, non-metals, and metalloids in terms of distinguishing properties
Explain the structure of the periodic table
Identify important families and elements
Describe atomic theory in terms of subatomic particles and location (nucleus, energy levels)
Define atomic number, mass number, isotope, and atomic molar mass and be able to identify these for a given element
Determine numbers of protons, neutrons and electrons for a given element
Describe the process of ionization and formation of cations and anions
Identify patterns in the periodic table for valence electrons and energy levels
Relate ionization to the octet rule

4. The Elements 115: basic building blocks
90 naturally occurring, 25 synthetic
Split into 3 classes
Metals
Non-metals
Metalloids

5. Metals Most elements Silver/grey and shiny
Conductors of heat and electricity
Malleable and ductile
Most solid at room temperature
Reactivity varies
Inert= unreactive

6. Non-Metals 17 elements Grouped based on their different from metals
Vary is state, color and reactivity
Highly reactive= fluorine
Inert= noble gases
About half will appear at molecules (more than one atom)

7. Metalloids Remaining elements
Properties intermediate between metals and non-metals
Along the staircase (except aluminium)
Ex. Silicon, arsenic, boron

8. The Periodic Table

9. The Periodic Table Organizes elements based on chemical properties
Metals on left side and centre
Non-metals on far right
Exception hydrogen (learn more later)
Metalloids between two
Shows name and symbol for element
Get to know the symbols!

10. The Element Game
For the following, identify as being a metal, non-metal or metalloid
Hydrogen
Sulfur
Calcium
Tin
Gold
Boron
Aluminum
Xenon

11. Pre-test For the following, give the element’s name or symbol: Calcium
Hydrogen
Sulfur
Phosphorus Mg Na

12. Important Families
Groups of elements with similar chemical/physical properties
Group 1: alkali metals
Soft, shiny, silver, very reactive with water
Compounds white and soluble in water
Group 2: alkali earth metals
Shiny, silver
White compounds but not as soluble

13. Important Families cont…
Group 17: halogens
Non-metals
Very reactive
React with alkali metals to make salts
Group 18: noble gases
Very unreactive

14. Periodic Table Homework
You need to fill in the periodic table and colour it.
Include family names
Periods
Metals, non-metals, metalloids

16. Atomic Theory Atoms are very small (10-10 m in diameter)
What are three kinds of subatomic particles? Where are they found?
Protons and neutrons are over 99.9% of total mass
Imagine this: our classroom filled with iron. If we take out the nuclei for all the iron atoms and place them side by side, they would be as big as a period in a book. But that period would almost equal the mass of the room full of iron

17. Atomic Number Number of protons Determines the element
Can you find the atomic number of the following elements? Pb Hg
tin
chlorine
platinum Cu
manganese
lithium
As we move through the periodic table, what do you notice about the ordering of atomic numbers?

18. Mass Number and Isotopes
Isotope- atoms of same element with different number of neutrons
Ex. Common form of hydrogen has one proton and no neutrons. 1/ hydrogen atoms have a neutron, called deuterium (“heavy” hydrogen)
Each isotope given a mass number
Equals total number of protons and neutrons (don’t include electrons- too small)
# of neutrons= mass number – atomic number

19. Mass Number and Isotopes cont…
Can be shown as:
Mass number
element symbol
atomic number
Ex. Oxygen-16
What would be the symbols for oxygen-17? Oxygen- 18?

20. Mass number and isotopes
Name:
#p = _____
#n = _____
#e = _____
Name:
#p = _____
#n = _____
#e = _____

21. Practice: Fill in the chart!
Element Name
Mass Number
Number of Protons
Number of Neutrons
calcium 41
uranium
238
aluminum 14 9 5 19 10
iron 27

22. Atomic Molar Mass Shown in the periodic table
Average mass of element’s isotopes
Number of electrons equals number of protons (in neutral atoms)
Atomic molar mass

23. Energy Levels Electrons occupy energy levels
Region around nucleus either empty or contain electrons
Increase energy when get further from the nucleus
Specific number of electrons/level
First level- 2 electrons
Next levels- 8 electrons
Energy level can be empty, partly or completely filled

24. Review What are the three subatomic particles in an atom?
What particles make up most of the mass?
How are electrons arranged?
How many electrons can be in the first energy level? Second?
What is an isotope? How can we find number of neutrons in an atom?
How do we know how many electrons we have?

25. Drawing Atoms Drawings include: Ex. Magnesium atom Oxygen Calcium
Number of protons
Number of neutrons
Electrons in correct energy levels (how many electrons can be in each level?)
Ex. Magnesium atom
Oxygen
Calcium
Chlorine
Argon
Carbon-14

26. Valence Electrons Electrons in the outermost energy level
Valence number- number of electrons an element can lose/gain to combine with other elements
How many valence electrons do each of the following elements have?
Oxygen?
Magnesium?
Chlorine?
Argon?
Carbon-14?

27. The Octet Rule For understanding how atoms bond
Atoms want to have eight electrons in their valence shell (which shell is this?)
More stable when have full energy levels
What are these elements like with full energy levels?
Noble gases!
Gain/lose electrons to be like their closest noble gas
Ex. Chlorine will gain one electron to be like argon
Exception: hydrogen, lithium and beryllium. Why? Who do they want to be like?

28. What Now?
When we gain/lose electrons from an atom, what happens to its charge?
Ex. Fluorine gains one electron to fill its outer octet. What is its electrical charge now?
Gaining/losing electrons process called ionization
Results in positively charged or negatively charged ions

29. Formation of Ions
Elements can lose or gain outermost (valence) electrons
Called ionization
Makes ions (positively or negatively charged)
Allows metals and non-metals to form compounds
eature=related

30. Cations Positively charged ions Metal ion loses electrons
Where do the electrons go?
To another atom
Why would the atom be positively charged if it loses electrons?
Ex Magnesium
Loses 2 electrons
What would the diagram look like before? After ionization?
Put charge as a superscript: ex. Mg2+

31. Anions Negatively charged ions Non-metal gains electrons
Where do the electrons come from?
From atoms that lose electrons (cations)
Why is it negatively charged?
Ex. Oxygen
Gains two electrons
What is the diagram before? After ionization? How would you write it as a symbol?

32. Naming Ions Cations: Anions: Element name + ion Ex. sodium ion
Ex. magnesium ion
Anions:
First part of element name and change ending to “ide”
Ex. nitride
Ex. oxide
Ex. fluoride

33. Practice
For each of the following ions, draw with nucleus and electrons and give appropriate name or symbol:
Hydrogen ion
Cl-
Nitride
Be2+
sulfide

34. Ion Trends in Periodic Table
group 1 = 1+
group 2 = 2+
group 3-12 labeled on table
group 15 = 3-
group 16 = 2-
group 17 = 1-
group 18 not ions
B, C, Si do not form ions

35. Why form ions? Why do atoms gain or lose electrons?
To have full energy levels and be more stable like closest noble gas
Once ions are formed:
Electrically charged
What would happen when I bring a cation and an anion together?
Form a bond! How we make compounds between metals and non-metals
Need to form the ion first before a bond can be formed

36. Question What is the difference between an atom and an ion?
How can I tell the difference with our diagrams?

37. Practice: Fill in Chart!
Atom or Ion Name
Overall Charge
Number of Protons
Number of Electrons
Symbol
#Electrons lost or gained
Mass Number
# of Neutron
oxygen atom O 16
oxide ion 10
O2-
potassium ion 19 39 F 2+ 20 40

38. Review Animation
Gizmo to show ionic bonding and octet formation with charges esource&ResourceID=514&certificate=authorizer%3DLearnAlberta%26userid% 3DLA05%26i%3D0%26expires%3D2010%252F09%252F10%2B10%253A35%25 3A20%26hash%3DxJ9JAV5TTO7PpNXmbZmpHg%253D%253D