Atomic structure and the Periodic Table

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Atomic structure and the Periodic Table
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Notes Write down important vocabulary words
as we go through todays Power Point.
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Element song
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ReviewSubatomic Particles as listed in a block
on the period table.
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Proton p, positively charged particle, in
nucleus.Neutron no, no charge , in nucleus.
Electron e-, negatively charged particle, in
electron levels, filled by lowest energy levels
first with a max pair in each energy level.
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Atomic number the number of protons. Average
Atomic mass the number of protons plus the
average number of neutrons in the nucleus.
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Isotopes atoms of an element with differing
amounts of neutronsThe average atomic mass is
the average mass of a mixture of isotopes that
occur in nature.
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Ions atoms of an element with differing amounts
of electrons.If electrons do not equal protons,
we call it an ion, not an atom.Ions will have a
positive or negative charge.Do not confuse ions
and isotopes. Ions different amounts of
electrons.
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An atom has no charge so there is an equal number
of electrons and protons. Remember that the mass
is the total number of neutrons and protons.
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Bohr ModelingBohr Models are one of the most
used models. Even though the orbit shapes are
not correct, the model is very useful and
explains most chemical behavior.
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Bohr Models
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The Bohr Model of the Atom One of the simplest
working models of the atom is that developed by
Niels Bohr. In this, a central nucleus containing
protons and neutrons is orbited by electrons. The
electrons are arranged in shells or energy
levels.
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Bohr Model1. Nucleus in the center with protons
and neutrons.2. Electrons in different orbit
levels.3. Larger Orbits represent electrons with
more energy.
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Electrons in shells nearer the nucleus have lower
energy than those farther away.
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Todays model of an atom is a dense positively
charged nucleus surrounded by a negative cloud of
electrons and is based on probability
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Electron cloud - the region around the nucleus
of an atom with a 90 or high probability of
finding an electron
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http//www.orbitals.com/orb/orbtable.htm
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Periods there is a period for each electron
level.1st electron level only has 2 atoms.
2nd electron level only has 8 atoms. 3rd
electron level has 18 atoms.
1s1
1s2

2s2
2p6
3s2
3s6
3d10
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Groups or Families Up and Down Have Similar
Properties. Look at back of book, on top of Group
for group name. Left side is group 1 or 1A. US
uses number 1, Europe uses 1A. Right side is
group 18.
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Left Group 1 is called Alkali Metals. Left 2nd
Group 2 is Alkaline Earth Metals. Rightmost Group
18 is Noble Gases.
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Electron Dot Structure
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Electron dot structure represent the electrons
in the outermost shell
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Never more then 8 dots, these dots will allow us
to predict how the element reacts
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How many dots would go around these atoms?
Cl Li Na Mg C