Atomic Structure

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Atomic Structure
Inner electron shell
Proton
Nucleus
Neutron
Outer electron shell
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Sub Atomic Particles

• 1. PROTONS- positive electrical charge, found in
  the NUCLEUS, or center of an atom.
• 2. NEUTRONS- neutral (no electrical charge), also
  found in the NUCLEUS.
• 3. ELECTRONS- negative electrical charge, found
  moving around the nucleus in the ELECTRON CLOUD

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Friendly electrons

• Electrons like to travel in pairs, when they can
  find another electron to travel with.
• Different layers within the electron cloud are
  called ENERGY LEVELS or SHELLS

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Friendly electrons

• Electrons like to travel in pairs, when they can
  find another electron to travel with.
• Different layers within the electron cloud are
  called ENERGY LEVELS or SHELLS

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Atomic Number?
How many bonds will this form?
How many Protons?
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Electron shells

• The first shell can hold 2 electrons.
• The second shell can hold 8 electrons.
• The third shell also holds 8 electrons.

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Electrons exist in shells around the nucleus.
H 1 p (1 e-) He 2 p (2
e-) Li 3 p (3 e-) C 6 p
(6 e-) N 7 p (7 e-) O
8 p (8 e-)
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How to find atomic structure

• ATOMIC NUMBER protons in the nucleus
• Each different atomic number is a new ELEMENT, or
  pure substance that cannot be broken down

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How to find atomic structure

• ATOMIC MASS protons PLUS neutrons in the
  nucleus
• Atomic Mass- Atomic Number neutrons

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Periodic Table
Alkali Metals
Halogens
Noble Gases
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Information in the Table
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Atomic number Name of the element Elemental
Symbol
Silver
Ag
107.87
Atomic mass (weight)
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• 109 elements are currently known
• (Dont need to know this!)
• 87 are metals
• 26 are radioactive
• 16 are man made (all radioactive)
• 11 occur as gases
• 2 occur as liquids

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Navigating the Periodic Table

• The rows are the periods
• Each period starts a new shell of electrons
• The periods are numbered starting with 1 at the
  top
• The columns are the groups
• Each group has similar chemical properties
• The groups are numbered starting with 1 at the
  left
• Elements with similar properties have the same
  number of electrons in the outermost shell

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Chemical Families

• Chemical Families
• Group 1 are called alkali metals because the
  react with water to from an alkaline solution,
  very soft metals.
• Group 7 are the halogens
• These need only one electron to fill their outer
  shell
• They are very reactive.( disinfectants, bleach,
  headlights)
• Group 0 are the noble gases as they have
  completely filled outer shells
• They are almost non reactive.