Nanoparticles

• What are nanoparticles defined by?

  Diameter between 1 nm and 100 nm
• Why are coarse particles also called dust?

  Because they have a diameter of PM₁₀
• What is the diameter range for fine particles?

  100 nm to 2500 nm
• What is nanoscience?

  A field studying uses and properties of nanoparticles
• How does the surface area to volume ratio change as particles decrease in size?

  The ratio increases as size decreases
• How do you calculate the surface area to volume ratio?

  • Surface area to volume ratio = surface area ÷ volume
• What is the surface area to volume ratio of a cube with sides of length 100 nm?

  0.06 nm⁻¹
• What is the surface area to volume ratio of a cube with sides of length 10 nm?

  0.6 nm⁻¹
• How does the surface area to volume ratio change when the side length of a cube increases from 10 nm to 100 nm?

  The ratio decreases by a factor of 10
• Why do nanoparticles have different properties compared to bulk materials?

  Due to their high surface area to volume ratio
• What is one application of nanoparticles in medicine?

  Delivering drugs directly into cells
• What property do silver nanoparticles have?

  Antibacterial properties
• Why are nanoparticles used in cosmetics?

  To improve moisturisers without greasiness
• What is a concern regarding the health effects of nanoparticles?

  Their long-term impacts are not fully understood
• What should products containing nanoparticles do according to public concern?

  Be clearly labelled for consumer choice
• How do nanoparticles in sun creams compare to traditional sun creams?

  They protect better against harmful UV rays
• What is a potential environmental concern regarding nanoparticles?

  They might damage the environment when washed away
• What is one application of nanoparticles that can conduct electricity?

  Used in tiny electric circuits for chips
• What is one risk of using nanoparticles in medicine?

  Unknown long-term health effects
• Which nanoparticles are suitable for making car windows that defrost quickly?

  Silver nanoparticles conduct heat effectively