Download Unit 1 Atomic Structure

Unit 1 Atomic Structure
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Objectives:
List the three major parts of an atom.
State the law of charges.
Discuss the law of centripetal force.
Discuss the differences between
semiconductors and insulators.
Unit 1 Atomic Structure
History
The Greeks were the first to discover
electricity 2500 years ago. The Greeks
called amber elektron.
About 300 years ago Charles DuFay studied
the force of repulsion and attraction
using a glass rod.
Unit 1 Atomic Structure
List of charged materials.
Unit 1 Atomic Structure
Unlike charges attract and like charges repel.
Unit 1 Atomic Structure
Atoms
The atom is the basic building block of the
universe.
An element is a substance that cannot be
chemically divided into a simpler
substance.
The principal parts of an atom are the
electron, neutron, and proton.
Unit 1 Atomic Structure
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Atomic Theory
An element is composed of only one type of
atom.
The atomic number of an element is the same
as the number of protons in the nucleus.
The Periodic Table of Elements lists all the
types of atoms or elements known to mankind.
A molecule is the result of the joining of two or
more different types of atoms.
Unit 1 Atomic Structure
Water can exist in three states.
Unit 1 Atomic Structure
Table of elements.
Unit 1 Atomic Structure
The three principal parts of an atom are the
electron, the neutron, and the proton.
Unit 1 Atomic Structure
The electron has a negative
charge and orbits the
nucleus.
The proton has a positive
charge.
The neutron has no charge
and combines with the
proton to form the
nucleus.
Unit 1 Atomic Structure
Protons have a positive
charge.
Electrons have a
negative charge.
Unit 1 Atomic Structure
The Law of Charges
Opposite charges attract!
Unit 1 Atomic Structure
The Law of Charges
Like charges repel.
Unit 1 Atomic Structure
Centripetal Force prevents
an object from pulling
away from its axis point.
Unit 1 Atomic Structure
Electrons form orbits or shells that
surround the nucleus.
Unit 1 Atomic Structure
Electrons orbit the nucleus in a circular fashion.
Unit 1 Atomic Structure
Valence electrons are located in the
outer orbit of an atom.
Unit 1 Atomic Structure
A copper atom contains 29 electrons and has one
valence electron.
Unit 1 Atomic Structure
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Electron Flow
Electricity is the flow of electrons.
This happens when a free electron knocks
another electron free out of its orbit.
The striking electron settles into a new
orbit.
This process repeated many times creates
electrical flow.
Unit 1 Atomic Structure
An electron of one atom knocks an electron of
another atom out of orbit and takes its place.
Unit 1 Atomic Structure
The energy of the cue ball is transferred to the ball
being struck.
Unit 1 Atomic Structure
The energy of the striking electron is divided.
Unit 1 Atomic Structure
The energy of the cue ball is divided between the
other two balls.
Unit 1 Atomic Structure
The energy of the striking electron is divided among
the eight electrons.
Unit 1 Atomic Structure
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Semiconductors
Semiconductors are materials that are
neither good conductors nor good
insulators.
They contain four valence electrons.
When heated, their resistance decreases.
Two common materials are silicon and
germanium.
Unit 1 Atomic Structure
Semiconductors contain four valence electrons.
Unit 1 Atomic Structure
Molecules are formed when atoms are
joined together.
Unit 1 Atomic Structure
There are six basic methods for producing
electricity:
1. magnetism
2. chemical action
3. pressure
4. heat
5. friction
6. light
Unit 1 Atomic Structure
There are five basic effects electricity can
cause:
1. magnetism
2. chemical reactions
3. pressure
4. heat
5. light
Unit 1 Atomic Structure
Producing sound with electricity.
Unit 1 Atomic Structure
Insulators
• Insulators resist the flow of electricity.
• They contain seven or eight valence
electrons.
• Examples of insulators are: rubber, plastic,
glass, and wood.
Unit 1 Atomic Structure
Review:
1. The atom is the smallest part of an
element.
2. The three basic parts of an atom are the
proton, electron, and neutron.
3. Protons have a positive charge, electrons
a negative charge, and neutrons no
charge.
Unit 1 Atomic Structure
Review:
4. Valence electrons are located in the outer
orbit of an atom.
5. Insulators are materials that do not
provide an easy path for electron flow.
6. Insulators are made from materials
containing seven or eight valence
electrons.
Unit 1 Atomic Structure
Review:
7. Semiconductors contain four valence
electrons.
8. Molecules are formed by joining atoms
together.
9. Semiconductors are materials that are
neither good conductors nor good
insulators.
Unit 1 Atomic Structure
Review:
10. Six basic methods for producing
electricity are magnetism, chemical
action, light, heat, pressure, and friction.
11. Five basic effects that can be caused by
electricity are magnetism, chemical
reactions, light, heat ,and pressure.
Unit 1 Atomic Structure
Review:
12. The law of charges states that like
charges repel and opposite charges
attract.