OZ 4

• Formation of ozone

  UV radiation absorbed by oxygen molecules to form O atoms, which react with O2 to form O3 (ozone)
• The ozone layer protects from harmful UV radiation from the Sun, absorbing most types of UV radiation including UVA, UVB, and UVC
• The video is in a revision format providing an overview of the content related to the ozone story topic in OCR RP Salters
• UVB radiation can lead to DNA damage, skin cancer, and sunburn, accelerating skin aging
• UVC is the worst UV radiation in terms of damage for humans, while UVA and UVB also have damaging effects
• Ozone is a protective layer found in the stratosphere formed when UV radiation from the Sun hits an oxygen molecule
• Breakdown of ozone

  UV radiation splits ozone back into O2 and O
• The video is on sustainability, energy, and matter presented by Chris Harris from Lurie Tutors
• Main types of UV radiation

  • UVA
  • UVB
  • UVC
• UVA radiation can cause skin cancer and accelerate the aging process by damaging DNA in cells
• UVB is needed for the production of vitamin D, essential for the body to use calcium effectively and develop strong bones
• UV tans the skin and helps protect deeper tissues from the effects of radiation
• Hydrocarbons and nitrogen dioxide, mainly from cars and factories, contribute to the formation of ozone in the troposphere
• Ozone in the stratosphere is good as it protects from harmful UV, but at lower levels in the troposphere, it can be harmful
• Ozone is toxic to humans and breathing it in is not recommended
• UVB

  UV is needed for the body to produce vitamin D, which is essential for using calcium effectively to develop strong bones
• Approximately 21% of dry air is made up of oxygen
• Deficiency in vitamin D may lead to issues with bone strength and formation
• Gas concentrations, such as ozone, can be measured in parts per million to monitor air quality
• Combination of solid carbon particulates and ozone forms photochemical smog, which is harmful to respiratory systems, animals, and plants
• Gas concentrations are often expressed in parts per million for practicality
• Darker skin pigmentation helps protect against harmful UV radiation compared to fair-skinned individuals
• Formation of ozone in the troposphere

  Sunlight, hydrocarbons, and nitrogen dioxide mix to form ozone in the lower levels
• Calculating parts per million of hydrogen in air

  Divide 0.00055 by 100 to get the value in one part of air, then multiply by a million to get the value in a million parts of air
• An oxygen molecule (O2) can break its bond when the right energy is absorbed, forming oxygen free radicals (O dot radical)
• Oxygen free radicals are produced when energy is transferred to electrons, breaking bonds
• Nuclear fusion occurs in the Sun and emits radiation
• The atmosphere absorbs some infrared and most ultraviolet radiation
• Only a specific frequency of energy will be absorbed to excite the electron to a higher energy level
• Electromagnetic spectrum

  • Radio waves, Gamma rays, Infrared, Visible light, Ultraviolet
• Electrons absorb energy from UV or visible light, moving to higher energy levels
• When the right energy is absorbed, bonds break and free radicals are formed
• Radiation in the atmosphere: Earth's atmosphere absorbs some radiation produced by the Sun
• Radiation absorbed by the surface of the Earth is re-emitted back as infrared at a lower frequency, causing warming
• Combining equations for energy calculation

  Energy = (Planck's constant x Speed of light) / Wavelength
• All videos are free to use for helping students get the best grade
• Oxygen atom can also be considered as a radical (O dot radical)
• Calculation of energy given to a molecule by UV radiation

  Energy = Planck's constant x frequency
• Oxygen free radicals can be used to create the formation of ozone
• Calculation of frequency

  Frequency = Speed of light / Wavelength