What is the fundamental unit or main building block of all living things ?

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.

In 2002, the rare earth elements mine in mountain pass, california was closed because

What is the percentage of hydrogen in c2h4