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pantera1 [17]
3 years ago
9

A sample of Francium-212 will decay to one sixteenth of its original amount after 80 minutes. What is the half-life of Francium-

212.
Chemistry
1 answer:
lbvjy [14]3 years ago
6 0

20 minutes.

The sample would lose one half the quantity of francium in each half-life.

1/16 = 1/2^{4} = 1/2 \times1/2 \times1/2 \times1/2

Thus a mass decrease by a factor of 16 would correspond to a period of four half-lives. It took 80 minutes for the sample to lose all these francium, therefore

t_{1/2} = 80/4 = 20 minutes.

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Technetium (Tc; Z = 43) is a synthetic element used as a radioactive tracer in medical studies. A Tc atom emits a beta particle
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Question in incomplete, complete question is:

Technetium (Tc; Z = 43) is a synthetic element used as a radioactive tracer in medical studies. A Tc atom emits a beta particle (electron) with a kinetic energy (Ek) of 4.71\times 10^{-15}J . What is the de Broglie wavelength of this electron (Ek = ½mv²)?

Answer:

6.762\times 10^{-12} m is the de Broglie wavelength of this electron.

Explanation:

To calculate the wavelength of a particle, we use the equation given by De-Broglie's wavelength, which is:

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Putting values in above equation, we get:

\lambda =\frac{6.624\times 10^{-34}Js}{\sqrt{2\times 9.1094\times 10^{-31} kg\times 4.71\times 10^{-15}J}}

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Answer:

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