One problem with fuel-cell cars is that gas is not readily available in
pure form.
Answer here

What substance has a mass of 9.5g and volume of 2.1cm^3

What is the percentage of hydrogen in nitrogen trihydride

Astable electron arrangement for an atom is one that does not easily change. how is this arrangement arrived at? a. valence electrons are transferred or shared to create a full outer shell of electrons. b. valence electrons are discarded into space to create a full outer shell of electrons. c. protons (positive charge) pair with valence electrons (negative charge) to create a strong bond. d. outer shells with valence electrons are transferred or shared.