More on Atoms

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More on Atoms
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Size

• Atoms are minuscule!
• The diameter of one atom is on average 10-10m,
  that is a tenth of billionth of a meter
• Example
• 1 drop of water
• 1 700 000 000 000 000 000 000 atoms

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Arrangement

• Nucleus Protons and Neutrons
• Rings Electrons

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Rings AKA Shells AKA Orbitals

• Electrons are always moving- they spin around the
  nucleus
• They can move in any direction as long as they
  stay in their shell
• The atomic shell (or ring or orbital) is the
  distance from the nucleus that the electron spins
  
• The electrons in the first orbital is always
  closer to the nucleus than an electron in the
  second orbital

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Orbital Basics

1. A shell can called an orbital or energy level.
2. Shells are areas that surround the center of an
   atom.
3. Electrons live in something called shells.
4. Each of those shells has a name.

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• K shell Can hold a max. of 2 electrons
• L shell Can hold a max of 8 electron
• M shell Can hold a max of 8 electrons for the
  first 18 elements, and up to 18 after that
• Most any shell can hold 32

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Where are the electrons RIGHT NOW?!?!?!

• Yes electrons reside in specific shells
• BUT we can't really say exactly where an electron
  is at any moment in time. We can only approximate
  where an electron is located.
• According to quantum theory, an electron can be
  found anywhere around the nucleus.
• Using advanced math, scientists are able to
  approximate, that electrons are in a general
  area.
• These general areas are called the shells.

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Power Up

• Electrons are very important in the world of
  electronics.
• These very small particles stream through wires
  and circuits creating currents of electricity.
• Electrons move from negatively charged parts to
  positively charged ones.
• Negatively charged pieces of any circuit have
  extra electrons while the positively charged
  pieces want more electrons.
• The electrons then jump from one area to another.
  
• When the electrons move, the current can flow
  through the system.

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Molecules Compounds

• A molecule is a group of atoms that are
  chemically bonded
• e.g. A molecule of water (H2O) is made from a
  chemical bond between 2 atoms of hydrogen and 1
  atom of oxygen

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Combining Atoms to Make Molecules
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And some get very large
Glucose molecule
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Chemical Formulas

• Molecules are represented by their chemical
  formulas.
• This shows the nature and the number of each atom
  that composes the molecule.
• Each atom is represented by its symbol from the
  periodic table.

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• The number of each atom is written directly after
  the symbol. (the number 1 is not written)

The symbol for hydrogen
The symbol for oxygen
H2O
The absence of a number only 1 atom of oxygen
in the molecule
The number 2 2 atoms of hydrogen in the molecule