Ahuman hair is about 50 um thick. a pet flea is about 1 mm in size. how
many times smaller is the thickness of a human hair than a flea?

Which is the most likely way an automotive engineer would use chemistry

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as