Where it all is. 1856: John Newlands discovered that elements had repeating patterns of chemical...
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Transcript of Where it all is. 1856: John Newlands discovered that elements had repeating patterns of chemical...
Where it all is
1856: John Newlands discovered that elements had repeating patterns of chemical and physical properties. LAW OF OCTAVES
1869: Dmitri Mendeleev arranged the first one based on Atomic Masses and the Law of Octaves
1913: Henry Moseley Arranged the Modern Periodic Table based on Atomic Number.
1950: Glenn Seaborg developed the f block.
Groups or Families◦ Columns that go up and down.◦ There are 18 Groups
Periods◦ Rows that go across◦ There are 7 Periods
Highly reactive Replace Hydrogen in Water All have 1 valence electron All are s1
Forms +1 ions
Very reactive Don’t replace Hydrogen in Water
◦ Readily burn in O2 when exposed to heat Calcium makes up your bones. Batteries get their name from this group Have 2 Valence electrons
◦ All are s2 – forms +2 ions
These are the common metals All have d orbitals filling Less reactive than other metals Copper, Silver, and Gold least reactive Forms various positive ions
Have 3 Valence electrons◦ All are s2 p1
◦ All form +3 ions except Boron which forms a –3 ion
One is a metalloid (Boron) The rest are all metals
Carbon family has 4 valence electrons All are s2 p2
Composed of:◦ one non-metal (Carbon)◦ Two metaloids (Silicon and Germanium◦ Two metals (Tin and Lead)
Carbon always forms 4 bonds◦ All known life based on Carbon
Computers function based on Silicon and Germanium’s unique properties◦ They conduct electricity but not heat
Lead and Tin are common metals◦ Used to be used a lot in food storage
All have 5 valence electrons◦ All are s2 p3
Composed of:◦ two nonmetals - Nitrogen and Phosphorous◦ Two metalloids – Arsenic and Antimony◦ One metal - Bismuth
Nitrogen:◦ makes up most of the atmosphere◦ Critical to plant and animal life◦ Forms strong bonds that are used in explosives
Phosphorous◦ Critical to plant and animal life
All have 6 valence electrons◦ All are s2 p4◦ Usually form 2 bonds
Form – 2 ions (except Polonium +2, +4 ions) Composed of:
◦ 3 nonmetals – Oxygen, Sulfur, Selenium◦ 1 metalloid – Tellerium◦ 1 metal - Polonium
All have 7 valence electrons◦ All are s2 p5◦ Forms 1 bond
Forms – 1 ions All are nonmetals Highly reactive
◦ Never found in nature as single atoms◦ When pure will form F2, Cl2, Br2, I2
All have 8 valence electrons◦ All are s2 p6◦ Rarely form bonds
Never form ions◦ Helium, Neon, Argon have never been found in a
compound◦ Krypton, Xenon, Radium can sometimes be forced
to form compounds – but these are very unstable
Called Rare Earths◦ They are rare on earth - Most are manmade
All are radioactive All elements greater then Uranium (92) are
manmade Some are used in medical research
METALS Left of Staircase Ductile Form positive ions Lose electrons Malleable Conduct electricity and heat Shiny
NON METALS Brittle Dull Do not conduct electricity Do not conduct heat Gain electrons Form negative ions Right of staircase
Metalloids Also called semimetals Mix properties of both Silicon conducts electricity (metal) but not
heat (nonmetal). Silicon is shiny (metal), but brittle
(nonmetal)
Chemical Properties Elements in the same group will have
similar chemical properties. Elements in the same group have the same
number and arrangement of valance electrons
Elements lose and gain electrons to achieve the Noble Gas configuration