Science

• Safety is to prevent yourself from danger by following the rules
• Safety symbols/signs


  • Explosive
  • Oxidizing
  • Radioactive
  • Flammable
  • Harmful
  • Toxic
• Explosive symbol


  Means the container is explosive
• Oxidizing symbol


  Presence of oxidizing gases, solids or liquids that can intensify a fire
• Radioactive symbol


  To make everyone aware of a hazard in any area
• Flammable symbol


  Any flammable substances that ignite on contact with air
• Harmful symbol


  Used to show that a substance can be hazardous
• Toxic symbol


  Warns that a substance can cause severe damage
• Where safety symbols can be found

  • Institutions
  • Vehicles
  • Medicines
  • Chemical bottles
  • Electrical
  • Road
• Safety rules


  • Don't leave the gas on at home
  • Don't mix chemicals that you don't know about
  • Don't play with sharp objects in class
  • Don't cross the road without looking back
• Color codes for safety

  Red - dangerous substances

  Yellow - hazard/caution

  Blue - indicates an action should be done with caution

  Green - shows something is safe
• Don'ts in the lab

  • Food in the lab
  • Removing the fire extinguisher
  • No teacher
  • Sleeping
  • Exposed chemicals in a cabinet
  • Touching chemicals with hands
  • Putting things in electrical sockets
  • Chemicals near fire
  • Running
  • Spilling chemicals
  • Leaving cabinets and drawers open
  • Smelling chemicals
  • Leaving water running
  • No protective goggles
  • Chemicals on the edge of the table
  • Unorganized jars
• Dangerous situations: Playing around the stove, playing with scissors, exposed medicine, rat poison near food, lit cigarettes
• Precaution


  A measure taken in advance to prevent something dangerous from happening
• Examples of PPE (Personal Protective Equipment)

  • Gloves
  • Helmet
  • Protective padding
  • Mask
  • Hair net
  • Steel toe boots
  • Ear plugs
  • Goggles
  • Lab coats
  • Safety overalls
• Safety equipment in the lab

  • Safety shower
  • Eyewash station
  • Med kit
• If a chemical gets in the eye, use the eyewash
• Waste


  Unwanted materials to be discarded
• Categories of waste


  • Solid waste
  • Domestic waste
  • Electronic waste
  • Organic solvent waste
  • Corrosive waste (chemical)
  • Radioactive waste
  • Agricultural waste
  • Medical waste
• Proper disposal of waste is important to prevent pollution, disease spread, and environmental damage
• The scientific method is a systematic method that allows scientists to test their hypotheses and draw conclusions
• Hypothesis


  An assumption, an idea that's proposed for the sake of argument so that it can be tested to see if it might be true
• Focusing on evidence is important to find out how things work
• Osmosis


  The net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
• Water concentration


  The amount of water as compared to the other molecules like sugars or salts that are dissolved in that water
• Solutes are the dissolving molecules in water
• Solutes


  • Sugars
  • Salts
• Osmosis in cells


  Water particles diffuse from the outside of the cell (higher water concentration) down the concentration gradient into the cell (lower water concentration)
• Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration
• Osmosis is a special case of diffusion, specifically the diffusion of water molecules
• The key point is that water concentration is determined by the proportion of water compared to solutes, not the volume of water
• The cell's partially permeable membrane separates the inside of the cell from the outside
• The learning platform at www.anki.com has videos, practice questions and progress tracking for sciences and maths
• Engineers


  People who design and build things to solve problems
• Types of engineers


  • Civil
  • Mechanical
  • Electrical
  • Other types that don't exist yet
• Engineering process


  1. Define the problem

  2. Do research

  3. Develop a solution

  4. Design the solution

  5. Build a prototype

  6. Evaluate the solution
• Define the problem


  Figure out what the problem is that needs to be solved
• Example of defining a problem

  • Alexander Graham Bell trying to come up with a simpler, cheaper way for people to communicate
• Do research


  Make a list of questions, find information, look at existing solutions that could be improved
• Example of doing research

  • Alfred Nobel researching existing explosives to invent a safer one for miners