Science Exam Study Sheets

• Water table


  The level of water underground
• Zone of saturation


  The layer of rock or soil that absorbs water underground
• Spring tides


  Occur when the earth, moon, and sun are in alignment. The combined gravitational force of the sun and the moon cause a large tidal range
• Neap tides


  Occur when the sun and moon are at 90 degrees to each other
• Fluid


  Any substance that flows
• Viscosity


  A measure of a fluid's resistance to flow
• Density


  The relationship between a fluid's mass and its volume
• Buoyancy

  The ability or tendency to float in water or other fluids
• Force


  A push or a pull
• Mechanical advantage


  Increase in power
• Work

  The transfer of energy through motion measured in units of "Joules" (J)
• Cell


  The smallest unit of life
• Multicellular

  Cells that are specialized and organized and are more than one cell
• Unicellular


  Cells such as bacteria and is also only one cell
• Selectively permeable


  Some substances are able to pass through the membrane, while other substances are not able to pass through
• Soil holds the most amount of water at 74.4ml and gravel with 37.85 and sand at 32ml. Gravel can absorb the most water.
• A large surface area allows a soil to hold more water.
• States of water


  • Liquid
  • Gas
  • Solid
• Changes of state


  1. Evaporation

  2. Condensation

  3. Evaporation

  4. Precipitation

  5. Percolation
• When water evaporates, other things leave the water. When the water is in the clouds, the stuff can stay there when the water leaves.
• In the winter, the water is going to be warmer and in the summer they will have cooler summers.


  It takes longer to heat up then to cool down
• pH range of acids


  • Carbonated H2O
  • Lemon juice
  • Vinegar
• pH range of bases

  • Distilled H2O
  • Bleach
  • Liquid soap
  • Tap H2O
  • Baking soda
• The 2 gases that cause acid rain are sulfur dioxide, water and carbon dioxide. A low pH would also cause acid rain.
• Filtering air pollution in cars or in factories can prevent acid rain.
• Cold water sinks because it's more dense when warm water rises because it's less dense. As cool water sinks it pushes the warm water upward causing a current.
• Convection currents are important because they move nutrients from one area to the other. For example, oxygen from the air enters the top layer of water and is brought to organisms in deeper water by currents.
• We need to be careful with our water supply because it is a limited resource.
• Ways to reduce water consumption

  • Take shorter showers
  • Not leave the water on when brushing teeth
  • Don't just dump water down the drain
• Solids


  Particles are packed really close together
• Liquids and gases


  Particles are spread further apart
• Solids have a definite shape and volume, liquids have a definite volume but not shape, and gases have neither a definite shape or volume.
• Particle Theory explanation for a can of hairspray being thrown in a fire


  The pressure being put in the can expands and pushes against the can. The can explodes and the chemicals in the hairspray cause the fire to get bigger. The forces of attraction got weaker, so it exploded. The motion of the particles go faster.
• Density formula

  Density = Mass/Volume
• The density of water is 1 g/cm3. Some objects would float because their density is less than 1 g/cm3. The reason things in the ocean float that are bigger than 1 g/cm3 is because the salt in the water makes it more dense.
• Pascal's Law states that when pressure is put on a confined fluid equal pressure is created at all points. If the smaller syringe had force put on it and the larger starting was 3x bigger, then the 3x the pressure would be put on the large syringe.
• System


  A set of organized parts that work together to fulfill a specific purpose
• Input


  The materials or energy required by the system
• Output


  The result of the system
• Types of systems


  • Mechanical
  • Political
  • Biological
  • Transportation