Sciencespeaking topic
Mineral filter (zinc oxide, titanium dioxide) or chemical filter? One is thought to reflect the rays, but actually both mostly absorb them. So where is the real difference, and why is it still called 'physical'?
— sunscreen chemistry / UV filter mechanism
practice with this topic
Set the timer (5-30 min), take 20 seconds of prep if you like, start talking. Jot your thoughts onto the sticky-note board.
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