1. Atoms and The Periodic Table
Learning Targets:
Describe atoms
Use the Periodic Table

2. Atoms
What are atoms?
Atoms are the basic building blocks of matter that make up everyday objects. A desk, the air, even you are made up of atoms!
There are 90 naturally occurring kinds of atoms. Scientists in labs have been able to make about 25 more.

3. Structure of Atoms All atoms are made of a nucleus, or center
surrounded by orbits of electrons

4. The nucleus
is made up of 2 kinds
of particles:
Protons-which have a positive charge. The number of protons determines what element you have.
Neutrons-- which have no charge. The number of neutrons usually matches the number of protons, but isotopes of an element may have different numbers of neutrons.

5. Around the nucleus of an atom, are orbits of electrons.
Electrons are very small, negatively charged particles. Their negative charge attracts them to the positively charged protons in the neucleus.

6. With your partner, describe these 3 particles that make up all atoms:
Electron
Proton
Neutron

7. Electron orbits exist in several shells or energy levels.
First energy level
Second
energy
level

8. Scientists often illustrate the electron arrangement with a drawing called a Bohr diagram. This shows the placement of the electrons into their energy levels.
Atoms like to have their outside energy level full. If it is not, they are more likely to react with other atoms.

9. Elements react when they give, take or share electrons from other elements.
Water is formed when 2 hydrogen atoms share electons with 1 atom of oxygen

10. Discuss with your partner:
How are electrons arranged?
What does a Bohr diagram show you?
What is likely to happen if elements DON’T have their outer electron level full?
What happens when one atom reacts with another atom?

11. Clues to the answers to these questions can be found
What would you expect different elements to be like?
Which elements are most likely to react?
What will they be likely to react with?
Clues to the answers to these questions can be found
in a tool called
THE PERIODIC TABLE.

12. The Periodic Table Organization of the Elements

13. Search for Order 1750 only 17 elements known
1789 Antoine Lavoisier grouped known elements (4 groups)
Metals
Non-metals
Gases
Earths
Next 80 yrs scientists looked for better way to classify known elements

14. Mendeleev’s Periodic Table
1869….Dmitri Mendeleev (Russian teacher and chemist) organized known elements while playing solitaire
Made deck of cards with elements
Listed name, mass and properties
Paid attention to how elements reacted in chemical reactions

15. Mendeleev’s Periodic Table
Strategy for organization: What did he look at?
chemical properties
physical properties
atomic mass
density
color
melting point
Valence electrons (sec 5.3)

16. Mendeleev’s Proposal
Elements arranged in rows based on increasing mass.
Elements with similar properties are in same column.
Chart was a Periodic Table - arrangement of elements in columns based on a set of properties that repeat.

17. Mendeleev’s Prediction
Table incomplete– elements not yet discovered
Left spaces in table for undiscovered elements
Good models allow for predictions to be made based on model
Used properties of nearby elements to predict properties of unknown elements

18. He called this element eka-Aluminum.
Later it was renamed Gallium after its discovery in 1875

19. Evidence Supporting Mendeleev’s Table
Close match between Mendeleev’s predictions and the actual properties of new elements showed how useful table was.
Ex. Discovery of: Aluminum, Gallium, Scandium, and Germanium

20. The Modern Periodic Table
YOU NEED 3 DIFFERENT COLORED PENCILS
Section 5.2
The Modern Periodic Table
The Elements by Tom Lehrer

21. The Modern Periodic Table
“Periodic” - Repeating patterns
Listed in order of increasing number of protons (atomic #)
Properties of elements repeat
Periodic Law- when elements arranged by increasing number of protons, properties repeat in pattern

22. Columns in the Periodic Table
-vertical (up & down)
-called groups or families
-#ed 1-18 or 1A through 8A
-elements in same family have similar properties

23. Rows in the Periodic Table
-horizontal (left – right)
-called a period
-properties change greatly across period
-first element in period is very active metal
-last element in most periods is noble gas
-7 periods (number them on your periodic table)

25. Discuss with your partner:
Why is a chemists chart called a PERIODIC table—what does periodic mean?

26. 6 C Carbon 12.01 For example: Carbon has atomic # 6
Element Key
Important information about an element is given in each square of the periodic table:
its atomic number
chemical symbol
element name
average atomic mass
6 C Carbon 12.01
For example:
Carbon has atomic # 6
(or has 6 protons), an average atomic mass of and a symbol of C

27. What are 4 important pieces of information each square of the Periodic Table gives you about its element?

28. Metals Most solids (Hg is liquid) Luster – shiny.
Ductile – drawn into thin wires.
Malleable – hammered into sheets.
Conductors of heat and electricity.
Include transition metals – “bridge” between elements on left & right of table

29. Non-Metals Properties are generally opposite of metals
Poor conductors of heat and electricity
Low boiling points
Many are gases at room temperature
Solid, non-metals are brittle (break easily)
Chemical properties vary

30. Metalloids stair-step pattern
Have properties similar to metals and non-metals
Ability to conduct heat and electricity varies with temp
Better than non-metals but not metals

32. Representative Groups
Section 5.3
Representative Groups
Hip Hop Classroom
The Elements

33. What are Valence electrons?
outermost e-’s
Responsible for chem props
Elements in same group…
same # of VE
ALL atoms want full outer
energy level (usually 8 VE)
To get full outer energy level, some elements:
lose e- (metals)
gain e- (non-metals)
share electrons (some non-metals & metalloids)

34. What are valence electrons?
Why are they important?

35. Introducing the ten major groups (families) on the modern Periodic Table:

36. Hydrogen is not a member of this group.
Alkali Metals
potassium
- 1 valence electron (VE)
- soft, silver-white, shiny metals
never found pure
most reactive metals
Reactivity increases down group
Hydrogen is not a member of this group.
It is not a metal.
reactivity increases

37. Label the Alkali Metals to your PT

38. Alkaline Earth Metals - 2 VE - not as reactive as alkali metals
magnesium
- 2 VE
- not as reactive as alkali metals
often mixed with Al
forms strong/light weight alloys

39. Alkaline Earth Metals Magnesium Calcium
Used to make steel (light metal w/o losing strength)
photosynthesis (chlorophyll)
Calcium
bones & teeth
Chalk, limestone, pearls, plaster

40. Label the Alkaline Earth Metals to your PT

41. Boron Family -3 VE Boron Hard/brittle never found pure in nature
in borax...used to make detergents & cosmetics

42. Boron Family 13 Al Aluminum 26.98 Aluminum
most abundant metal in earth’s crust
important metal for industry
light, strong, slow to corrode
13 Al Aluminum 26.98

43. Label the Boron Family on your PT

44. Carbon Family 4 VE Can gain 4 e-, lose 4 e-, or share e-
silicon
4 VE
Can gain 4 e-, lose 4 e-, or share e-
Most compounds in body contain C
Si 2nd most abundant element in Earth’s crust
Si used to tip saw blades

45. Label the Carbon Family on your PT

46. Nitrogen Family 5 VE Tend to gain 3 e- N and P used in fertilizers
Arsenic
5 VE
Tend to gain 3 e-
N and P used in fertilizers
P on tips of matches

47. Label the Nitrogen Family on your PT

48. Oxygen Family 6 VE Tend to gain 2 e- O very abundant element
sulfur
Oxygen Family
6 VE
Tend to gain 2 e-
O very abundant element
S used in fertilizers
O needed for digestion

49. Label the Oxygen Family on your PT

50. Halogen Family (“salt-former”)
-7 VE
-most active nonmetals
-never found pure in nature
-react with alkali metals easily (forms salts)
-F most active halogen

51. F compounds in toothpaste Cl kills bacteria
Halogens cont…
bromine
F compounds in toothpaste
Cl kills bacteria
I keeps thyroid gland working properly

52. Label the Halogen Group on your Periodic Table

53. The Noble Gases (Inert Gases)
Neon
- non-reactive
outermost e- shell is full (8 VE)
In “neon” lights
-in earth’s atmosphere (less than 1%)

54. Label the Noble Gases on your Periodic Table

55. Discuss:
What are chemical “families”?
How are they different from periods?

56. Transition Metals ductile, malleable, conductors
mercury
Almost all solids at room temp (Hg exception)
ductile, malleable, conductors
VE varies
Less Reactive than Groups 1 & 2
Fe, Co, and Ni produce magnetic field

57. Label the Transition Metals on your periodic table

58. Rare Earth Elements Lanthanide series (period 6)
uranium
Lanthanide series (period 6)
Actinide Series (period 7)
Some radioactive
Separated from table to make easy to read/print
silver, silvery-white, or gray metals.
Conduct electricity

59. Label the Lanthanide Series on your PT

60. Label the Actinide Series on your PT

61. You may watch more videos about the elements at:
or sing along at:
elemental funkiness - Mark Rosengarten
hip hop classroom

62. Did you reach our learning targets? Describe atoms
Use the Periodic Table
Use the table to describe oxygen.