Question

Assertion: Tritium is used as tracer element in preference to deuterium.
Reason: Tritium is non-toxic and it emits low energy beta radiation.

• A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion
• B. Both Assertion and Reason are true and Reason is not the correct explanation of Assertion
• C. The Assertion is true but Reason is false
• D. The Assertion is false but Reason is true

Answer 1

Answer: (A)

Both Assertion and Reason are true and Reason is the correct explanation of Assertion

The tritium beta decay to $3He$ (mean beta particle energy $5.7$ keV; decay energy $18.6$ keV) can be easily detected or can cause some other compound to fluoresce.

Tritium is therefore used as a radioactive tracer element in biological research in the form of tritiated water $(H_{2}O$ or $T_{2}O)$ and also used in capsules surrounded by a fluorescing compound (e.g., zinc sulfide) to provide illumination which must be independent of the electricity supply.

For example, it is used in emergency exit signs, self-luminous airport runway and helicopter pad lights, and light wands for use in directing traffic.