What is the percent of composition by mass of hydrogen in nh4hco3 (gram-formualmass=79 grams/mole)?

Which statement describes both homogeneous mixtures and heterogeneous mixtures?

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.

What natural processes produce large quantities of co2