At the AAAS Family Science Days this weekend, Professor Jesse Kroll‘s research group, working with the MIT Center for Environmental Health Science, will present “Understanding Air: Climate Change & Air Pollution.” In this activity booth, visitors will first use LEGO bricks to model the composition and relative quantity of molecules in air, and then model complete and incomplete combustion of a hydrocarbon fuel. In the process, visitors will learn about the chemistry of the air and the origin of certain air pollutants (carbon dioxide, carbon monoxide, and particulate matter). Kroll’s group also will demonstrate how particulate matter sensors work. In addition to planners Kroll and postdoctoral associate Eben Cross, CEE participants include graduate student Kelsey Boulanger, postdoctoral associate Ellie Browne, and undergraduates Teri Oehmke, Sid Pai and Alex Severt. Family Science Days will be held from 11 a.m. to 5 p.m. at the Hynes Convention Center on Feb. 16 and 17.