Transcript Power point on the Periodic Table

THE PERIODIC TABLE
ATOMS
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Smallest unit of an element that has the
properties of that element
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Basic building blocks of matter
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Made of protons, neutrons, and electrons
ATOMS ARE MADE OF….
Sub-atomic particles!
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Proton: in the nucleus, symbol “p”, positive charge, much
larger mass than an electron
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Neutron: in the nucleus, symbol “n”, no charge, slightly
larger mass than a proton
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Electron: on shell's around the nucleus, negative charge,
symbol “e”
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Nucleus: dense central core of the atom, contains protons
and neutrons
IN A NEUTRAL ATOM…
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Number of protons is equal to number of
electrons
Number of protons that an atom of any element
has is called the atomic number
The sum of the protons and neutrons is called the
mass number
Protons and neutrons make up nearly all the
mass of an atom
Chemical symbols (e.g. “B”) are used to represent
elements
 Elements are listed in the periodic table by increasing
order of atomic number
 Horizontal rows in the periodic table: period
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Numbered from 1 to 7
 The period also tells you how many shells the element has
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Vertical columns in the periodic table: group
Numbered from 1 to 18
 Elements in the same family (group) share similar physical and
chemical properties
 The group also tells you the amount of valence electrons
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Example

Boron
Atomic Number
 Atomic Mass
 Drawing (with electrons)
 Finding protons/Neutrons
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CLASSIFICATION OF ELEMENTS

Metals, Non-metals, Metalloids
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Metals
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These metals have properties that you normally
associate with the metals you encounter in everyday
life:
They are solid (with the exception of mercury, Hg, a
liquid).
They are shiny, good conductors of electricity and
heat.
They are ductile (they can be drawn into thin wires).
They are malleable (they can be easily hammered
into very thin sheets).
All these metals tend to lose electrons easily.
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Non-metals
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have properties opposite those of the metals.
are brittle
not malleable or ductile
poor conductors of both heat and electricity
tend to gain electrons in chemical reactions.
Some non-metals are liquids.
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Metalloids
The elements within the stair-stepped line
 Have properties that are somewhat of a cross
between metals and nonmetals.
 Have unique conductivity properties (they only
partially conduct electricity)
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SPECIAL GROUPS
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Some groups have unique names….
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Group 1: Alkali metals
Group 2: Alkaline earth metals
Group 3 – 12: Transition metals
Group 17: Halogens
Group 18: Nobel gases