Share
Explore BrainMass

Particle Physics

1. In an electrolysis experiment, a student plated silver onto an electrode, maintaining a current of 1.600 A for 46.0 min. What mass of silver was deposited?

a. 4.94 g
b. 2.47 g
c. 11.2 g
d. .02 g

2. A sample of polonium has a half-life of 2.7 min and an intial activity of 1.0 x 10^6 Bq. What is its activity after 27 min have elapsed?

a. 980 Bq
b. 9800 Bq
c. 19,600 Bq
d. 22,000 Bq

3. What is the de Broglie wavelength of a particle moving at a speed of 1.00 x 10^5 m/s if it is (a) an electron (b) a proton? (me= 9.11 x 10^-31 kg and mp=1.67x^-27 kg.)

a. 0.727 nm and .000397 nm
b. 7.27 nm and .00397 nm
c. 1.25 nm and .00452 nm
d. 72.7 nm and .0389 nm

4. What is the minimum voltage required in an x-ray tube to produce photons whose wavelength is 1.0 nm?

a. 1.24 kV
b. 12.4 kV
c. 65.2 kV
d. 0.124 kV

5. What particle is emitted in the decay of 14C6 to 14N7?

a. electron
b. positron
c. gamma
d. alpha

Solution Preview

1)
I = 1.600 A
t = 46.0 min = 46.0*60 = 2760.0 sec

For silver
Electro-chemical equivalent
E = 4.0246g/amp-hr = 4.0246/3600 g/Amp.sec = .001118 g/Amp.s

Therefore, silver deposited
m = E*I*t = 0.001118*1.6*2760 = 4.94 gm --Answer (a)

2)
half-life T = ...

Solution Summary

This solution includes full calculations and answers for each question.

$2.19