The equation of radioactive decay

The half-life of Molybdenum-93 is 4000 years. A sample of Molybdenum-93 has a mass of 10 mg. When will the mass be reduced to 1 mg?

Image Source: Virtual museum of chemical elements.

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The quantum tunneling phenomenon


The quantum tunneling phenomenon is negligible in the classical mechanics.

Show that the tunneling probability equals 0 for an object of mass 0.007 kg moving at a speed of 0.1 m/s against a solid obstacle of height 0.05 m and width 0.01 m.

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De Broglie wavelength of an electron


What is the de Broglie wavelength of an electron that has been accelerated through a potential difference of 100 V?

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The path of an electron in a bubble chamber

70l9eThe diagram shows the path of an electron in a bubble chamber.

Which of the following can you deduce from the diagram?


(A) The electron is moving anti-clockwise.
(B) The electron is moving clockwise.
(C) The magnetic field is acting out of the page.
(D) The speed of the electron is increasing.

Source: The Student Room

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A mixture of two radioactive elements

PIA17841A mixture contains two radioactive elements with half lives of 800 and 1600 years respectively. If the relative proportion of radioactive elements is initially 1:1, what is their relative proportion after 1600 years?

Image credit: NASA/JPL-Caltech/CXC/SAO/ Radioactive Core of a Dead Star

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Does Light Accelerate?

lightBendsWe usually use the terms “light slows down” or “light speeds up” when we describe the behavior of the light in the media. We also know that light curves in a gravitational field and emits from an atom. Certainly, we are wondering, “Does light accelerate?”

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Do Particles Reproduce?


Image Credit: CERN.

Particles are not living organisms and do not grow or reproduce.
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