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JEE Main 20206 SeptemberMorning Shift
Exam
JEE Main
Year
2020
Date
6 September
Shift
Morning Shift
Subject
Chemistry
Chapter
p Block Elements (Group 15, 16, 17 & 18)

JEE Main 2020 · 6 September · Morning Shift · Chemistry · p Block Elements (Group 15, 16, 17 & 18)

The presence of soluble fluoride ion upto 1 ppm concentration in...

The presence of soluble fluoride ion upto 1 ppm concentration in drinking water, is :

Options

  1. Aharmful for teeth
  2. Bharmful to skin
  3. Charmful to bones
  4. Dsafe for teeth

Correct answer

D. safe for teeth

Step-by-step solution

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.
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