Notifications
Clear all
0
20/09/2020 5:11 pm
Topic starter
The presence of soluble fluoride ion upto 1 ppm concentration in drinking water, is :
(1) harmful to bones
(2) harmful to skin
(3) safe for teeth
(4) harmful for teeth
1 Answer
0
20/09/2020 5:13 pm
(3) safe for teeth
Explanation:
Soluble fluoride is often added to drinking water to make concentration upto 1 ppm because F– ions make the enamel on teeth much harder. But above 2 ppm cause brown mottling of teeth. Cause harmful effect on bones and teeth.