periodic table of elements. the elements naming elements most elements were named in latin symbols...
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PERIODIC TABLE OF ELEMENTS
The Elements
Naming Elements Most elements were named in latin Symbols for the elements are derived from
latin name Determined by the International Union of Pure and
Applied Chemistry (IUPAC) New elements are given a temporary 3 letter symbol
until IUPAC decides on an appropriate 2 letter symbol This committee names new elements based on
where they were discovered or to pay tribute to a notable scientist
Common Elements and Symbols
A Brief History
Johann Dobereiner (1829)
Noted a similarity among the physical and chemical properties of several groups of three elements
Middle element had mass about halfway between the atomic masses of the other two – LAW OF TRIADS
John Newlands (1864)
Arranged all known elements in order of increasing atomic mass
Law of Octaves Noticed repeating physical and
chemical properties every 8 elements
Mendeleev (1869)
Dmitri Ivanovitch Mendeleev created the first accepted version of the periodic table.
He grouped elements according to their atomic mass; elements with similar properties appeared in same column
Blank spaces were left to add elements First periodic law: elements arranged
according to increasing atomic mass show a periodic recurrence of properties at regular intervals
Mendeleev’s Periodic Table
Modern Periodic Law
When the internal structure of atoms was discovered, Mendeleev’s periodic law was revised Elements arranged according to
increasing atomic number show a periodic recurrence of properties at regular intervals
Features of the P.T.
Groups Periods Columns of elements are
called groups or families. Elements in each family have
similar but not identical properties.
For example, lithium (Li), sodium (Na), potassium (K), and other members of group 1 are all soft, white, shiny metals.
All elements in a family have the same number of valence electrons.
Each horizontal row of elements is called a period.
The elements in a period are not alike in properties.
In fact, the properties change from metallic to non-metallic as you go across
Staircase line
Divides metals on left from non-metal on right
State of Matter Indicated by colour of the symbol
Black = solid Blue = liquid Red = gas
Families
Hydrogen
The hydrogen square sits atop Family 1, but it is not a member of that family. Hydrogen is in a class of its own.
It’s a gas at room temperature. It has one proton and one electron in
its one and only energy level. Hydrogen only needs 2 electrons to fill
up its valence shell.
Alkali Metals
Group 1 metals One valence
electron Most reactive
metals, react violently with water to make a base
soft, silver, solidsalkali metals in water
Alkaline Earth Metals Group 2 metals two valence electrons. React slowly with water Solid, react with air to form oxides React with H to form hydrides (except Be)
Transition Metals
Groups 3 - 12 Strong, hard metals High melting points good conductors of heat
and electricity. React with O to make
oxides Some react with acids Form multivalent ions
Halogens
Group 17 non-metals 7 valence electrons Extremely reactive with
hydrogen and metals Solid, liquid or gas Dull, do not conduct electricity
Noble Gases Group 18 non-metals Full valence shell gases that are extremely un-reactive
(stable) Low melting and boiling points
Lanthanides (rare earth metals)
Atomic # 57 - 70 Belong to period
(row) # 6 on the periodic table
Actinides
Atomic # 89 - 102 Belong to the 7th
period Include the
transuranic elements (elements with atomic #93 or greater – synthetic)