I need help QUICK!! 20 points Which of the following is/are formed as gravity pulls increasing amounts of dust and debris in a nebula together?

a. the solar wind

b. meteors

c. planetesimals

d. meteorites

Iron is a transition metal with multiple oxidation numbers. (answer the following) a. what is the iron (ii) ion? how does it differ from the iron (iii) ion? b. if iron were to bond with oxygen, predict the formula for each oxidation number of iron. c. how would each formula be named?