The Electrical Nature of Matter

1
The Electrical Nature of Matter

• Or
• Where do the charges come from?

2
Atoms are electrically neutral.

• In an atom, the number of protons, is equal to
  the number of electrons.
• For example Oxygen has 8 protons and 8
  electrons that means 8 -8 0
• What happens if . . .

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. . .that oxygen atom gains electrons?

• Oxygen has 8 protons and 8 electrons when an
  atom.
• For each electron you add, it adds more negative
  charge. Lets use the same equation
• 8 -9 (add an electron) -1
• 8 -10 (add 2 electrons) -2
• When the total charge is not zero, they are
  called IONs.

4
Loosing electrons makes you

• POSITIVE!!
• Since you are getting rid of (having fewer)
  negative charges, your overall charge is
  positive.

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Why is it that it is the electrons that are lost
or gained?

• Think about the picture of an atom you drew in
  middle school . . . .
• In the center or nucleus are the protons and
  neutrons. These are not changed by ordinary
  actions.
• But, what happens if you slide your feet across a
  carpet, when you have socks on?
• You just picked up loose electrons . . . .

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Losing and Gaining Electrons

• Electrons on the outer edges (Valence Electrons)
  are not being pulled very tightly by the protons
  in the nucleus
• Also atoms have certain configurations of outer
  electrons that they prefer THEY ALL WANT TO
  HAVE 8 ELECTRONS!!
• Atoms will loose or gain electrons to achieve
  these configurations forming IONS

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Valence Electrons- s p only
Atoms will lose or gain electrons to get 8
VALENCE e- (remember not 8 total, 8 outer e-)
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Metals Like to Lose

• Elements in group 1A, 2A, and 3A like to lose
  electrons (a.k.a. groups 1, 2, 13)
• Losing electrons
• Group 1 elements tend to have a ____ charge.
• Group 2 elements tend to have a ____ charge.
• Group 13 elements tend to have a ____ charge.

POSITIVE CHARGE ()
1
2
3
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Non-Metals Like to Gain

• Elements in group 15, 16, and 17 like to gain
  electrons
• Gaining electrons
• Group 15 elements tend to have a ____ charge.
• Group 16 elements tend to have a ____ charge.
• Group 17 elements tend to have a ____ charge.

NEGATIVE CHARGE (-)
- 3
- 2
- 1
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What about 4A and 8A??

• Elements in group 14 can go either way. They can
  either lose or gain 4 electrons, so they prefer
  to share . . .
• Lose electrons Gain electrons
• Group 18) have a very stable configuration and do
  not lose or gain electrons unless a great deal of
  energy is added. Therefore they do not form IONS.

4
- 4
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Mass Number

• The sum of the number of protons and neutrons in
  the nucleus of an atom of a particular element.
• Remember the number in the square is an average
  of all of the isotopes of that element.
• Isotopes have different numbers of neutrons, but
  the same number of protons

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For each element below, give protons, neutrons
and preferred ionic charge

• Bromine
• Carbon
• Sulfur
• Boron
• Lithium
• Chlorine
• Argon
• Hydrogen
• Germanium

• Sodium
• Aluminum
• Magnesium
• Fluorine
• Oxygen
• Potassium
• Calcium
• Silicon
• Arsenic