Matter And Energy

Matter is anything that occupies space and has mass. Energy is the ability of matter to do work.

  • Chemical Nature of Matter
              • Atoms - The smallest unit of matter which can exist. (there are currently 109 known elements)
                              • Protons - Are the positively charged elements of the atom.
                              • Neutrons - Are the neutrally charged elements of the atom.
                              • Electrons - Are the negatively charged elements of the atom.
                                              • Nucleus - Protons and Neutrons make up the center of the atom and the electrons orbit around it.
        • Molecules - The bonding of atoms create molecules. (Hydrogen is made of up of one electron and one proton)
  • Physical Nature of Matter
              • Solid -A solid has a definite volume and shame and is independent of its container.
              • Liquid- When changing from a solid to a liquid the volume does not change but the material can now conform to it's container.
                            • Liquids are also incompressible
                            • Surface Tension - In a liquid the molecules still partially bond together
        • Gas- Gasses differ from solids and liquids in that they have neither a definite shape nor volume.
  • Weight and Mass
              • Weight - Weight is the force which gravity attracts a mass.
                          • The force of gravity varies with the distance between a body and the center of the earth.
    • Mass - Described as the amount of matter in an object and is constant regardless of its location.
                              • To find mass Mass = Weight / Acceleration due to gravity (32.2 feet per- second )
                              • Slug - is a unit of mass that is equivalent to the approximately 32.175 pounts under standard atmospheric conditions.
      • Density - The density of a substance is its weight per unit volume.
                        • The density of solids and liquids vary with temperature however the density of gas varies with temperature and pressure.
                        • To find Density Density = Weight / Volume
        • Specific Gravity - Is a comparison of one substance to that of another.
                            • Densities of solids and liquids are compared to water at 4 degrees Celsius and gasses are compared to air.
                            • Specific gravity is independent of the size of the sample under consideration and varies only with the substance the sample is made of.
                            • Hydrometer - Is a device used to measure the specific gravity of liquids.
  • Energy
            • Potential Energy - Energy stored in a material, even though the object is not doing work.
            • Kinetic Energy - When Potential Energy is release and causes motion it is changed to kinetic energy.
            • Units of Energy - Most common used to measure energy is the Horsepower and is equivalent to 33,000 foot pounds of work done in one minute. In the metric system is the Joule.

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