Mass, volume and density. -- Solubility and saturation points. -- Viscosity, flow rate and buoyancy. -- Simple machines. -- Gears, mechanical advantage, speed ratios and efficiency. -- Hydraulics and pneumatics. -- The role of cells within living things, cell-tissue-organ system. -- The microscope. -- Body systems, part 1. -- Body systems, part 2. -- Problems associated with body systems. -- Transmission and absorption of light. -- Reflection and refraction of light. -- Vision and lenses. -- Water in its various states affects earth's landforms and climate. -- Adaptations of aquatic ecosystems. -- Water quality.