Periods of Elements

1
Periods of Elements

• Chapter 5
• Lesson 5-3

2

• What two days are missing in Family 3 4?
• What is Family 5s name?
• What dates are included in the third period of
  the table?

3
PERIODIC TABLE

• Columns Families/Groups
• Vertical
• Rows Periods
• Horizontal

4

• Two Bottom Rows
• Should be between Families 2 and 3 in Periods 6
  and 7
• Didnt fit on the page

5
Period

• One of the horizontal rows
• Made up of a series of elements
• with increasing atomic numbers
• Show patterns of physical and chemical properties
• Periodic Table has 7 periods (rows)

6
Stair-Step Line

• Located on right side of table
• On left, are metals (except hydrogen)
• On right, are non-metals (mostly gases)

7
Metals

• Shiny
• Solid at room temp, except mercury
• Conductors of heat and electricity
• Usually 1-3 electrons in their outer shell
• Lose valence
• electrons easily

8
Non-Metals

• Mostly gases
• Non-metal solids are
• easily crushed
• are not shiny
• Usually 4-8 electrons in their outer shell
• Gain or share valence electrons easily

9
Non-Metals

• Most active are upper right corner
• (not counting noble gases)
• Non-metals gain electrons from other elements,
  instead of losing them
• Closer the outer energy level is to the nucleus
  the easier it is to attract electrons
• Fluorine is most reactive non-metal

10
Metalloids

• Between metals and non-metals

11
Metalloids

• Properties of both metals and non-metals
• Dull in color
• Not malleable or ductile
• Conduct heat and electricity
• but not as well as metals
• Semiconductors

12
Metalloids

• Used to make
• (1) transistors
• (2) integrated circuits
• (3) other critical parts of electronic devices

13
Reactivity of Elements

• Alkali metals near bottom are the most reactive,
  especially lower left corner.
• Outer electrons are so far away from the nucleus
  that the attractions between protons and
  electrons is weak, so the elements lose electrons
  easily

14
The Chernobyl Disaster

• Worst accident at a nuclear power plant
• April 26, 1986
• Chernobyl was in the Soviet Union, but now the
  Ukraine

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• Result of a flawed reactor design
• Operated with inadequately trained personnel
• Lack of cultural safety

16

• Graphite caught fire and caused an explosion
• Steam explosion and fire
• released at least five percent of the radioactive
  reactor core
• atmosphere and downwind
• Caused great deal of damage
• Released large amounts of harmful radioactive
  material
• 31 people died from radiation sickness or burns
• More died in following years due to accident
• http//www.youtube.com/watch?vbSRC1_OZPIg (9
  minutes)
• http//www.youtube.com/watch?v4-Kt5RvdJQQfeature
  related (5 minutes)

17
Strontium-90

• Radioactive material carried by wind into
  northern and central Europe
• Isotope of strontium with half-life of 28 years
• Takes place of calcium in chemical reactions

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• Effects on the Human Body
• Strontium-90 enters body and replaces calcium and
  exposes bones to radiation
• Strontium-90 exposure cause serious damage to
  bone marrow
• Strontium-90 causes leukaemia
• Strontium-90 enters bodies same way as calcium
• When grass grows it absorbs calcium from the soil
• Cows eat the grass and make milk, then we drink
  it
• Body absorbs calcium
• Milk had to be thrown because of high levels of
  radioactive material
• http//www.youtube.com/watch?vrvAJ_u3Q0Hwfeature
  related (313 minutes)

19
http//www.ourtimelines.com/hist/chernobyl.jpg

• http//www.youtube.com/watch?vnMKUnOWY3ZQNR1
  (538 minutes song)

20
Bibliography

• Aldridge, Bill, Jack Ballinger, and Albert
  Kaskel. Teacher's for Use with Science
  Interactions Course 3. 3rd ed. Vol. Course 3. New
  York Glencoe/McGraw-Hill, 1998.
• "Chernobyl." World Nuclear Association. May 2008.
  15 Jan. 2009 lthttp//www.world-nuclear.org/info/ch
  ernobyl/inf07.htmlgt.