the periodic table atomic structure and. history of the periodic table mendeleev (1860’s) –...
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The Periodic Table
Atomic Structure and
History of the Periodic Table
Mendeleev (1860’s)– Developed the first periodic table– It was arranged by atomic mass– He was able to predict properties of elements
Moseley- developed the modern periodic table, arranged by atomic number (number of protons)
Memory Trick: M & M created the periodic table…
Left of zig zag
On the zig zag
Right of zig zag
METALS
METALLOIDS
NONMETALS
II. Organization (your Roadmap)
A. Metals- Nonmetals- Metalloids-
Characteristics of Metals• Hard• Shiny• Conduct heat and electricity well• Includes the transition and inner-transition metals
– Inner transition metals include the lanthanoids and actinoids
Characteristics of Nonmetals• Are gases or brittle solids at room temp.• Surfaces are dull• Insulators
Characteristics of Metalloids• Have properties of both metals and nonmetals
Period vs. Group
• Period – All elements in a horizontal row– 7 periods on the periodic table
• Group– All elements in a vertical column– Sometimes called “families” because they share
similar properties
The Periodic Table-Elements are arranged according to increasing atomic number
-rows are called periods-columns are called groups
**The group number of an element will tell you the number of valence electrons for groups 1-2 and in groups 13-18 the number of valence electrons is 10 fewer than the group number (except for helium which only has 2 valence electrons)For groups 3-12, other methods are used to determine their valence electrons.
Examples:
-Hydrogen is in Group 1 so only has 1 valence electron
-Oxygen is in Group 16 (16-10) so only has 6 valence electrons
-Iodine is in Group 17 (17-10) so has 7 valence electrons
Group 1 (IA) – Alkali Metals-most reactive of all elements- only has 1 valence electron in outer shell
Group 2 (IIA) – Alkaline Earth Metals- very reactive- only has 2 valence electrons
Group 17 (VIIA) – Halogens- very reactive, never found uncombined in nature, tends to bond with metals to
form salts
Group 18 (VIIIA) – Noble Gases- unreactive since stable. Outer shells are filled by valence
electrons. Colorless, odorless gases
TRANSITION “Group B”
INNER TRANSITION
Group A & B
REPRESENTATIVE“Group A”
Group A- RepresentativeGroup B - Transition