Help me with this please

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

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?

What ions are formed when hcl dissolves in water?