If a piece of iron is placed in pure nitrogen, nothing happens. if the in is exposed to air, it begins to rust. what conclusion can you make about air, based on this observation?

Alandscaper is shopping for landscaping materials. she wants to use materials through which water flows easily. which materials should she choose? check all that apply. clay gravel granite rocks with cracks loosely packed soil

The total amount of energy contained in an object

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? ab c d