Pls help its really hard to do

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

Why do cells appear different in distilled water than they do in 10% salt water?

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