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How Things really Work The
Physics behind Everyday Life
Tues July 7: Afternoon Session
2: 12:30 – 3 PM . Chemical and
Electrical Properties of Matter
Learning Objectives:
•Understand that chemical reactions are important to everyday life
•Understand the basic structure of an atom and which parts are involved in a
chemical reaction
•Understand difference between a physical and a chemical property change.
•Understand how static electric works and relate to the chemical properties
(electron configuration) of an atom or molecule
Lab 1 Understanding Chemical and
Electrical Properties of Matter
• Theory: The understanding of the
chemical and electrical properties of
matter requires the understanding of two
fundamental theories. One is called the
kinetic theory of matter the other is the
atomic theory.
•
Kinetic Theory of Matter
• The Kinetic Theory of Matter is a conceptual model that
states that the basic particles of matter at the scales of
atoms and molecules are in vigorous motion. The Kinetic
Theory assumes three rules:
• (1) All matter is composed of small particles.
• (2) The particles of matter are in constant motion.
• (3) All collisions between the particles of matter are
perfectly elastic
Atomic theory
• The atomic theory, states that the fundamental
building blocks (small units of any element) is
the atom which are made up of protons and
neutrons at their center and electrons on the
outer edge. ALL chemical reactions and
electrical properties only involve the movement
and interaction of electrons. See figure 2.
•
Fundamental Components of the
Atom - how the relate to charge
Quantum Mechanics
Quarks and Strings
• More recently it has been discovered that
protons, neutrons are made up of more
fundamental particle called quarks.
• And the fundamental quark and electron
particles are now thought to be made up of
small rubber band type structures called
strings.
• This involves the branch of physics called
Quantum Mechanics (See figure 3)
Lab 2
Lab 3: Creating models of atoms
and simple molecules
• Models are very useful tools to understand
concepts of process that we can't see. You
will use the simple Bohr Model of atoms to
explore the structure of inorganic and
simple organic models. You will also look
at the two type of bonds, covalent (shared
electrons) and ionic (transferred
electrons).
http://en.wikipedia.org/wiki/File:Ionic_bonding_animation.gif
http://www.youtube.com/watch?v=QqjcCvzWwww
Methane Molecule
Lab 4: Understanding how
Molecules dissolve in Water
• Molecules dissolve easily in water if they are of
the same shape and also if they have an ionic
nature.
• We will examine molecules that do and don't
dissolve in water by using your atomic and
molecular models to track what is happing when
salt, sucrose sugar and oil is placed in water.
• We will also mix baking soda with vinegar to
examine distinguish between physical and
chemical changes. reactions
http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf
Lab 5. Using model to track
hydrolysis reaction
Lab 6 Static Electricity Lab 1:
(from Lab 102 Exp 1)
•
When a substance gives up or take on an electron the object becomes electrically charges.
•
Charges with the same sign ( "like charges" ) repel each other, whereas charges of opposite sign
("unlike charges") attract each other. This is a consequence of Coulomb's Law.
•
When two objects are charged by rubbing, they acquire equal and opposite charges. This is a
consequence of Charge Conservation.
•
Coulomb's law
•
Law of charge conservation: Charge can nether be created or destroyed only moved.
•
Conductors: Allow their electrons to move freely.
•
Insulators are objects in which there are essentially no electrons that are free to move
•
Induced Charge: Charging a conductor
•
Faraday Cage: We use the device called a "Faraday cage" to give us a relative measure of static
charge. Basically it is a wire with a cylindrical (conducting) cage that approximates an an ideal hollow
conductor (all charge resides on the surface) at one end, and an instrument called an electrometer at
the other end (Fig x). We know that the electrons inside a conductor rearrange themselves when one
end of the conductor is near a charged object. When a charged object is inserted into the cage, the
cage becomes charged and the other of the wire (inside the electrometer) becomes oppositely charged.
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Lab 6 Magnetism
• A magnetic force field surrounds magnets and
electric currents, and is detected by the force it
exerts on moving electric charges and on
magnetic materials. Magnetism acts a lot like
static charges, but there are some differences.
• The first is the cause . The magnetic filed that
cause magnetism, is cause by moving electrical
charges (electric currents).
• There are always two poles of any magnet.
Lab 6 Magnetism
• A magnetic force field surrounds magnets and
electric currents, and is detected by the force it
exerts on moving electric charges and on
magnetic materials. Magnetism acts a lot like
static charges, but there are some differences.
• The first is the cause . The magnetic filed that
cause magnetism, is cause by moving electrical
charges (electric currents).
• There are always two poles of any magnet.
Declination
Earth has internal electric
current in molten outer core
causing a magnetic field.