Science Grade 8 Final Exam

• Pressure


  When pressure is applied to a liquid, the spaces between the particles decrease
• Dissolving instant coffee


  Coffee granules are more attracted to the water particles than to one another
• Solid


  • The particles of a solid cannot move around freely
  • The particles that make up solids have enough energy to pull away from one another
  • When poured, some solids will form a pile
  • Solids have a definite volume
• Boiling point


  At its boiling point, a liquid becomes a gas
• Pure substance


  A pure substance is a substance in which all of the particles are identical
• Solubility


  The amount of solute that can dissolve in a given amount of solvent at a given temperature
• Viscosity


  Viscosity decreases as a liquid is heated, and increases as it is cooled
• Density


  The mass per unit volume of a substance
• Metal sinks in ethyl alcohol

  The metal has a higher density than the ethyl alcohol
• Life jacket


  The life jacket lowers the average density of the wearer
• Submarine diving


  Increasing the water in the ballast tank decreases the average density of the submarine
• Buoyancy


  The ability of a fluid to support an object in or on the fluid
• Spreading force over double the area

  The pressure on the object will be halved
• Liquids are incompressible in an enclosed area
• Photosynthesis


  The process of making food using carbon dioxide, water, and energy from the Sun
• Characteristics of living organisms

  • They respond and adapt to their environment
  • They reproduce
  • They grow
• Without reproduction, life could not continue
• Chloroplasts


  The part of the plant cell responsible for producing food through photosynthesis
• Carrying a microscope by its arm and base is the correct procedure
• Organelles


  The structures inside of cells
• Chloroplasts


  The organelle present only in plant cells, and never in animal cells
• Animal cells do not have a cell wall
• Selectively permeable


  Allows some particles to pass through but not others
• The cell membrane that does not allow any particles to pass through it is impermeable
• Vascular tissue


  The xylem and phloem tissues
• Xylem tissue


  Responsible for transporting water throughout the plant
• Arteries


  Blood vessels with thick, muscular walls for carrying blood under pressure
• Alveoli and capillaries


  Gases are exchanged between the two
• Villi


  They increase the surface area of the small intestine, thus allowing more absorption to occur
• Muscles are not part of the nervous system
• White blood cells


  The component of blood responsible for defending the body against infection and disease
• Incandescent light source


  Produces excess heat
• Bioluminescence


  The production of light by living organisms
• Ray


  A straight line that represents the path of a beam of light
• Angle of incidence


  Equal to the angle of reflection
• Iris


  The coloured part of the eye
• Pupil reflex


  The natural adjustment in the size of the pupils
• Concave lens


  • Thinner in the middle, thicker edges
  • Causes light to converge
• Retina


  The structure in the human eye that mimics the role of film in a camera
• Force, distance, and work


  Work = Force x Distance