Question

i have a plan and design lab to do and i need help
-your grandfather has to do a barium metal test to help locate and diagnose a stomach ulcer. he is hesitant to swallow the suspension of barium sulphate because barium compounds are poisonous. however, the doctor told him that although barium compounds are toxic, barium can be safely used in the body. suggest a hypothesis for the doctor's statement and design an experiment to test your hypothesis .

Answer 1

Try comparing Barium to other similar atoms in the same row, such as calcium (both carry a 2+ charge). That's one idea.
Now, as to the doctors hypothesis, like most medicines which can be "toxic" but also safely used in the body, you could look at the benefits. Think about whether the benefits outweigh the consequences. If so, that could also be something to think about.