THE ELECTRICAL NATURE OF MATTER

1
THE ELECTRICAL NATURE OF MATTER
2
ELECTRICITY

• A FORM OF ENERGY THAT INVOLVES THE MOVEMENT OF
  ELECTRONS
• ELECTRONS ORBIT THE NUCLEUS OF AN ATOM
• ELECTRICITY IN ONE FORM OR ANOTHER IS ALL AROUND
  US. IT IS IN THE LIGHTNING IN THE SKY, THE STATIC
  CLING IN YOUR CLOTHES, THE SPARK BENEATH YOUR
  FEET WHEN YOU WALK ON CARPETS.

3
STATIC ELECTRICITY

• ELECTROSTATICS is the study of electricity at
  rest. It involves electric charges, the forces
  between them, and their behaviour in materials.

4

• ELECTRICAL FORCES arise from particles in atoms.
  A positively charged nucleus (containing protons
  neutrons) is surrounded by negatively charged
  orbits (containing electrons).

5
NEGATIVE POSITIVE CHARGE

• COMB
• -Acquires a negative charge
• WOOL SWEATER
• -Acquires a positive charge

6
LAW OF ELECTRIC CHARGES

• UNLIKE CHARGES ATTRACT
• LIKE CHARGES REPEL
• CHARGED OBJECTS ATTRACT UNCHARGED (NEUTRAL)
  OBJECTS

7

• Most atoms are considered neutral because they
  have the same number of protons and electrons.
• If one electron is removed from an atom, then it
  is no longer neutral. The atom now has more
  protons than electrons and it is said to be
  positively charged.

8
IONS

• A charged atom is called an ION. A positive ion
  has a net positive charge and has therefore LOST
  one or more electrons. A negative ion has a net
  negative charge and has GAINED one or more
  electrons.
• Electrons in the outermost orbits of an atom are
  bound very loosely and can be easily dislodged.
  The energy required for this to happen differs
  for different substances.

9
INSULATORS

• ARE MATERIALS THAT DONT ALLOW ELECTRONS TO MOVE
  ON OR THROUGH THEM.
• EX GLASS, COTTON, RUBBER, PLASTIC, PAPER

10
CONDUCTORS

• MATERIALS THAT ALLOW ELECTRONS TO MOVE FREELY.
• EX ALUMINUM, COPPER, GOLD, SILVER

• Insulators Conductors

11
TYPES OF ELECTRICITY

• (1) STATIC
• -BUILDS UP WHEN 2 DIFFERENT OBJECTS ARE RUBBED
  TOGETHER.

12

• FRICTION CAUSES ELECTRONS TO MOVE FROM ONE
  MATERIAL TO ANOTHER.
• THE OBJECT THAT GAINS ELECTRONS BECOMES
  NEGATIVELY CHARGED, AND THE OBJECT THAT LOSES
  OBJECTS BECOMES POSITIVELY CHARGED.

13
(No Transcript)
14
EXAMPLE SITUATION

• Electrons are held more firmly in rubber than in
  fur. Hence, when you stroke a rubber rod with a
  piece of fur electrons are transferred from the
  fur to the rod. The rod now has more electrons
  than protons and therefore is negatively charged.
• The piece of fur is now positively charged
  because it has lost its electrons and now has
  more protons than electrons.
• If you rub a glass or plastic rod with a piece of
  silk, you will find that the rod becomes
  positively charged. In this case, the electrons
  are transferred from the rods to the silk.