Why is this a scientific question?
"Do people perform better on exams when they wear their favorite color?"
The question is not specific
The question reflects an opinion
The question can be tested by a systematic procedure.
The question asks about phenomena that cannot be measured

Awic dietitian is meeting with a client who has an infant and a young child. the mother says that the young child is a very picky eater and will only eat crackers and juice. the health worker notices that the child's hair is brittle, his nails tear easily, and the skin inside his lower eyelids is very pale. these are all signs of iron deficiency.

Glutamic acid: hydrophilic or hydrophobic? positive, negative, or neutral? valine: hydrophilic or hydrophobic? positive, negative, or neutral?

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.