is motor oil a homogeneous mixture or a compound? why?

is iron smelting a chemical or physical process?

I call oil a homogeneous mixture. Look up the definition of a mixture and the definition of a compound. Motor oil contains a number of different "oils" as well as additives. It is homogeneous in that each spoonful you remove has the same composition as the next spoonful.
Iron smelting takes iron ore and changes it to iron metal. Look up the definition of chemical and physical change and then decide if this is a chemical or physical process. I hope this helps.

Thank you very much that really helped me.

You're welcome! Glad I could help.

You're welcome! I'm glad I could help. If you have any more questions, feel free to ask.

You're welcome! I'm glad I could help you. If you have any more questions, feel free to ask!