A great deal has been written on that, and opinions vary. I will just give you mine. 'Science' and 'scientific' are not themselves terms of science. Some philosophers have attempted to give the terms a clear meaning (Karl Popper, for example). I think they have failed. And I don't think that the ordinary language terms 'science' or 'scientific' are very clear or useful. So I would suggest that your questions aren't good ones. Further, there are many branches of natural science and many branches of the social sciences and there is probably little to be learnt from carving the whole lot into two groups and trying to compare and contrast them. Better: look at each branch of study that interests you and see if the theoretical claims are properly justified.