Physics

• Electricity flowing in a wire can create its own magnetic field
• Producing a magnetic field from electricity

  1. Electricity is electrons flowing

  2. Electrons are spinning in the same direction

  3. Spinning electrons produce a magnetic field around the wire
• Right-hand rule


  Used to determine the direction of the magnetic field produced by an electric current
• Using the right-hand rule

  1. Point thumb in direction of electric current

  2. Fingers curl in direction of magnetic field
• Applying the right-hand rule


  • Pen in right hand, thumb points in direction of current
  • Fingers curl to show magnetic field direction
• Determining magnetic field direction in a loop of wire

  1. Use right-hand rule at different points around the loop

  2. Magnetic field lines go out of page on one side, into page on other side
• Determining magnetic field direction in a clockwise current loop

  1. Use right-hand rule, fingers curl clockwise

  2. Magnetic field lines go into page
• Solenoid


  A loop of wire with many turns, creates a strong magnetic field
• Analyzing a solenoid using the right-hand rule

  1. Hold solenoid in right hand, fingers curl in direction of current

  2. Thumb points to north pole

  3. Magnetic field goes from south to north inside, north to south outside
• The right-hand rule is an important tool for understanding the relationship between electric current and magnetic fields
• In the previous lectures, we learned that when electricity flows, it produces a magnetic field
• Magnetic flux


  The amount of magnetism that a certain object is feeling
• Lewis diagram


  A way to see how many electrons an atom has in its outer shell
• Carbon


  • In row number two
  • Has six electrons in the first row
  • Has four electrons on the outside
• Bohr diagram


  A diagram that shows the inner shells of an atom
• Lewis diagram


  Only interested in the most outer shell of an atom
• Drawing a Lewis diagram

  1. Draw separate electrons in four separate locations

  2. If there are any leftover electrons, pair them up
• Lewis diagrams for different atoms

  • Fluorine
  • Boron
  • Sulfur
  • Neon
• Bonding


  • Electrons like to be in pairs of two
  • Atoms like to be surrounded by eight things (octet rule)
  • Hydrogen only likes to be surrounded by two things
• Bonding carbon and hydrogen

  1. Draw carbon with four separate electrons

  2. Add hydrogen atoms and bond them to the carbon's electrons to form pairs
• CH4


  The best way for carbon and hydrogen to bond is one carbon and four hydrogens
• In the next lesson, more time will be spent on how different atoms bond together, such as water (H2O), ammonia (NH3), and carbon dioxide