Plutonium reacts with an element.
Carbon ( from carbo `` coal '' ) is a chemical element with symbol C and atomic number 6 . Hydrogen is a chemical element with chemical symbol H and atomic number 1 . Nitrogen is a chemical element with symbol N and atomic number 7 . Plutonium . It reacts with carbon , halogens , nitrogen , silicon and hydrogen . Silicon is a chemical element with symbol Si and atomic number 14 .