Avogadro's number is derived from the number of carbon-12 atoms in 12.00 grams. In a chemical reaction, 3.0 moles of hydrogen react with 4.0 moles of oxygen to produce water. How many reacting molecules are present when the reaction starts ?

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.