science

• nature of light : light has dual characteristics that of a "wave"

  and that of a "particle"
• NOTE: light travels in waves called electromagnetic and transverse waves
• PROPERTIES OF LIGHT :

  1. light travels in a straight line
  2. it travels very fast
  3. we see things because they reflect into our eyes
  4. shadows are places where light is blocked
• solar :

  • sun, moon, earth

  lunar :

  • sun, earth, moon (causes light to reflect)
• NOTE : a prism shows that light which we ordinarily see as white, consists of different colors.
• dispersion : a phenomenon in which a prism separates white light into its component colors.
• NOTE : white light is not a single color ; it is made up of a mixture of the colors of the rainbow
• how rainbows are formed :

  • sunlight is split-up by raindrops (prism)
• longest wavelength - red (radiowave)

  shortest wavelength - violet (gamma rays)
• sources of light :

  • luminous
  • non-luminous
• classification of an object :

  • opaque
  • transparent
  • transluscent
• Heat and tempature :

  • heat is a thermal energy that flows between bodies or regions due to temparature difference.
  • heat flows from the hotter to cooler bodies. (it causes molecules to move)
• temparature : degree of hotness and coldness of a substance. it is also the measurement of the average kinetic energy of the particles

  coldness - abscence of heat
• NOTE : thermometer - mechanical / electrical device for measuring temparature. it was invented by Galileo Galilei
• summary : heat - form of energy

  temparature - measure of energy
• modes of heat transfer :

  1. conduction - direct contact
  2. convection - happens in gas / liquid
  3. radiation - travels in the form of waves; no direct contact
• conductors - fast transfer

  /

  convection

  \

  insulators - slow transfer
• changes and different charging processes :

  • atoms : building block of matter ; protons, neutrons, and electrons
  • electricity - an electric charged is an electrical property of matter that creates a force between objects (+/-)
  • low of conservation of charges - cannot be created or destroyed, but can be transferred deom one material to another.
• + -

  \ /

  FORCE

  attraction ; + -

  or

  repulsion ; ++ and --