The glow-in-the-dark dials on some watches and some keychain lights shine with e

Question

The glow-in-the-dark dials on some watches and some keychain lights shine with energy provided by the decay of radioactive tritium. Tritium is a radioactive isotope of hydrogen with a half-life of 12 years. Each decay emits an electron with an energy of 19 keV. A typical new watch has tritium with a total activity of 18 MBq.

1) What is the speed of the emitted electron?

2) What is the power, in watts, provided by the radioactive decay process?

3) What will be the activity of the tritium in a watch after 6 years, assuming none escapes?

Explanation / Answer

we know that
mass of electron = 9.10*10-31 kg

=> energy =1/2mv2

19*1000*10-19 =.5*9.1*10-31 * v2

=> v = 6.46*107 m/s

b)

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.