Why is magnesium useful as a structural element in frames of everything from cell phones to airplanes?

The ammonia molecule in the diagram has the observed bond orientation because

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample?

Jill is pushing a box across the floor. which represents the upward force perpendicular to the floor? a) fp b) ff c) fn d) fg