+ chapter 7 the periodic table chapter 7. + + organizing the elements prior to 1860 there were 63...
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Chapter 7
The Periodic Table
Chapter 7
+
+ Organizing the Elements Prior to 1860
There were 63 known elements
No know pattern had been determined
Although new elements might be accidentally discovered from time to time, it was generally believed that all of the elements had been discovered
+ Who Invented It???Dmitri Mendeleev
(1860’s) Found a pattern. When organized by
atomic mass Properties were periodic
(repeating pattern) Elements could be
predictedHowever, a few
elements did not fit...
+ Who Invented It??? Henry Moseley (1914) If the elements are arranged
by atomic number they fit! Our periodic table is
arranged by atomic number.
+ Periodic Law As more and more
elements have been discovered each new element has supported periodic law
“Chemical and physical properties of elements are periodic functions of their atomic numbers.”
C & P properties repeat and can be predicted!
+
Groups (families) From top to bottom, or
column Elements in a family have
similar physical properties
Periods From left to right, or row Elements follow a
repeating pattern (periodicity) as you go from left to right, each element changing its reactivity and other properties based on this pattern
29
Cu
47
Ag
79
Au
Gold, silver and copper share similar properties and belong in the same group Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
HeH
++ + _ __
+
Group 1- Alkali Metals Group 2- Alkaline Earth Metals Groups3-12- Transition Metals Group 17- Halogens Group 18- Noble Gases
+ Three Classes of Elements
Metals Left side of the table Shiny, malleable, ductile, conduct heat and electricity
Nonmetals right side of the table Dull, brittle, poor conductors
Metalloids Either side of zigzag line (there are six of them) Have some of the properties of metals, but not all, properties can change under certain conditions (semi-conductors)
Metals lithium, calcium, iron,
gold, aluminium
Nonmetals carbon, oxygen,
helium, neon
Metalloids boron, silicon,
germanium, arsenic, antimony, tellurium
+
Also called…
_______________
Groups of the Periodic TableA
lkal
i Met
als
Alk
alin
e Ea
rth
Met
als
Transition Metals
Lanthanides
ActinidesH
alog
ens
Nob
le G
ases
HMetals
Metalloids
Nonmetals
Rare-Earth Metals
B
Si
Ge As
Sb Te
+ Group 1: Alkali MetalsMetalsOnly 1 electron in their outer levelVery Reactive-will easily give up
their electronSoft, silver colored, shiny, low
densityExamples: Li, Na, K, Rb, Cs, Fr
+Group 2: Alkaline Earth Metals Metals 2 electrons in outer level Very Reactive, but less reactive than
Group 1 (have 2 electrons to give up) Silver colored, more dense than Group
1 Examples: Be, Mg, Ca, Sr, Ba, Ra
+Groups 3-12: Transition Metals Metals 1 or 2 electrons in outer level
Reactive, but less reactive than Group 1 or Group 2
Shiny, good conductors of heat and electricity, more dense than Group 1 or Group 2
Examples: Ni, Cu, Pt, U
+Lanthanides and Actinides Transition Metals in Periods 6 and 7
Moved to the bottom to make room.
Lanthanides follow lanthanum (La)
Actinides follow actinium (Ac)
+Group 13: Boron Group 1 Metalloid / 4 Metals
3 electrons in outer level
Reactive
Solid at room temperature
Examples: B, Al, Ga, In, Tl
+ Group 14: Carbon Group 1 Nonmetal / 2 Metalloids / 2 Metals
4 electrons in outer level
Reactivity varies
Solid at room temperature
Examples: C, Si, Ge, Sn, Pb
+Group 15: Nitrogen Group 2 Nonmetals / 2 Metalloids / 1 Metals
5 electrons in outer level
Reactivity varies
All but Nitrogen (N) solid at room temperature
Examples: N, P, As, Sb, Bi
+Group 16: Oxygen Group 3 Nonmetas / 1 Metalloid / 1 Metal
6 electrons in outer level
Reactive (trying to get a full shell)
All but oxygen (O) are solid at room temperature
Examples: O, S, Se, Te, Po
+Group 17: Halogens All Nonmetals 7 electrons in outer level VERY Reactive Bad conductors of heat and
electricity React violently with Alkali Metals
(Group 1) to make “salts” such as NaCl
Never found alone in nature, always as a “salt”
Examples: F, Cl, Br, I, At
+Group 18: Noble GasesAll Nonmetals8 electrons in outer level (2 for
Helium)Not ReactiveColorless, odorless gasesUsed in light bulbs (Argon, Xenon,
Neon, Helium)Examples: He, Ne, Ar, Kr, Xe, Rn
+ Hydrogen: Its Own Group Part of Group 1, but unique. Nonmetal 1 electron in outer level Reactive (easily gives up
electron) Colorless, odorless gas at
room temp. Reacts explosively with
oxygen. Used in rocket fuel. Most common element in the
universe Hydrogen atoms cause acidity
+A
lkal
ine
Eart
h M
etal
s
Transition Metals H
alog
ens
Nob
le G
ases
H
Alk
ali M
etal
s
Lanthanides
Actinides
Alk
alin
e Ea
rth
Met
als
Hal
ogen
s
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