Question

A dental disease characterised by mottling of teeth is due to the presence of certain chemical element in drinking water. Which of the following is that element?

• A. Fluorine
• B. Boron
• C. Mercury
• D. Chlorine

Answer 1

The correct option is A Fluorine

Fluorides comes out during the refining of various materials and cause fluorosis. It is a disease, which is defined by mottling of teeth, abnormal bones that are liable to fracture, because flourine replaces Ca ${}^{2+}$ and makes the bones brittle. Flouride pollution is a serious problem in many districts of Rajasthan, where excess of flouride in water adversely affects the health of man. Many villagers have aged prematurely or developed hunch backs.

So, the correct answer is option A.