Why is barium carbonate toxic while sulphate not?

Barium carbonate is toxic due to its high solubility in water, which allows it to be easily absorbed by the body.

Once absorbed, barium can interfere with the normal function of cells by displacing calcium ions from their binding sites. This can lead to a variety of health problems, including muscle weakness, paralysis, and even death.

In contrast, barium sulphate is relatively insoluble in water, and therefore, it is not easily absorbed by the body.

As a result, barium sulphate is much less toxic than barium carbonate. In fact, barium sulphate is commonly used as a radiocontrast agent in medical imaging procedures, due to its ability to block X-rays and provide a clear image of the internal organs.