skincare 2.5 Flashcards
uv light
a high energy form of light present in sunlight, it has enough energy to break bonds
what can overexposure of sunlight cause
sunburn and premature ageing
how to stop sunburn and premature ageing
sunblock provides a chemical and physical barrier stopping uv light from reaching the skin
when are free radicals formed
when uv light breaks bonds
free radicals
atoms or molecules that are highly reactive due to the presence of unpaired electrons
what do free radicals cause
chain reactions because they are reactive
the three steps of chain reactions
initiation, propagation and termination
free radical scavengers
molecules which react with free radicals to prevent chain reactions occuring
what are free radical scavengers added to
cosmetics, plastics and foods