beaker_icon.png source=PhET notes=made using Photoshop
concentrationGraph_icon.png source=PhET notes=made using Photoshop
lightBulb_icon.png source=PhET notes=reused from faraday
magnifyingGlass_icon.png source=PhET notes=made using Photoshop
pHMeter_icon.png source=PhET notes=simplified screen capture of pH meter
pHPaper_icon.png source=PhET notes=screen capture of pH color key