Définition de la pollution de l'air​

Which is a chemical property of iron? a. it forms iron oxide (rust) when exposed to moisture and air. b. it is a gray–black metal that is hard to the touch. c. it has a melting point of 2795°f (1536°c). d. it is a good conductor of heat

All of the following are part of the biosphere except

Write the chemical formula for a compound that is made of an element from group 1 and an element from group 17