Atoms and Elements

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Atoms and Elements
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Elements

• The building blocks of matter
• Over 111 elements currently known
• Examples
• Carbon
• Oxygen
• Nitrogen

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Symbols

• Either 1 or 2 letters symbols
• First letter Capital, second lower case
• Some based on Latin name
• Example Latin
• C Carbon Au Gold-aurum
• O Oxygen Lb Lead-plumbum
• Mg Magnesium K Potassium-kalium
• Br Bromine Na Sodium-natrium

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Structure of an Atom

• Nucleus the center of an atom contains
• Protons
• Atomic mass 1
• Charge ()
• Neutrons
• Atomic mass 1
• Charge none

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Structure of an Atom

• Outside the nucleus electron
• Electron
• Atomic mass 0
• Charge (-)
• nucleus
• (containing protons
• and neutrons)

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Structure of an Atom

• Electrons are arranged
• in orbits
• Orbit 1 holds
• 2 electrons
• Orbit 2 holds
• 8 electrons
• Orbit 3 holds
• 8 electrons

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The Periodic Table

• Elements are arranged by size and chemical
  properties.
• Rows
• Period
• Size
• Columns
• Group
• Properties

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Properties

• Properties are related to atomics structure.
• The number of electrons in the outer most orbit
  (valence electrons) determine how an atom will
  behave in chemical reactions.

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Reading the Periodic Table