B. a nucleus with a positive charge.
Answer: I would say its either exit door or the last one.
Explanation: Hope this helps plz mark brainliest.
Geology is the science of Earth.
Ecology is the science of relationship between an organism and its environment.
Astronomy is the science of studying astronomical objects.
Whereas, Phrenology is the study of relating the size of human skull like its size, shapes e.t.c to his/her personality. So, its not a science as there is no scientific relationship between it.
Salt=compound, soda=liquid solution, aluminum foil=element, milk=colloid,
steel=solid solution
