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. + + + + + + + - + - + - - + - - - 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.