What is the difference between the probability and the probability density?

Short Answer

Expert verified

Probability is a number defining chances of and event to occur whereas probability density is distribution of probability over a region in space.

Step by step solution

01

Concept Used

Difference between probability and probability density is same as difference between charge and charge density.

02

Explanation

Probability: Chances of occurrence of an event is defined as Probability.

More is the likeliness of an even to happen, higher is it's probability.

Probability density is more of a distribution term. If probability of something is distributed over a length or region then probability density comes into play.

For example: Finding and electron in the region x=1 to x=5 will have different probability densities throughout this region.

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Most popular questions from this chapter

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A thin solid barrier in the xy-plane has a 10μmdiameter circular hole. An electron traveling in the zdirection with vx=0m/spasses through the hole. Afterward, is it certain that vxis still zero? If not, within what range is vxlikely to be?

In one experiment, 6000 photons are detected in a O.10-mm- wide strip where the amplitude of the electromagnetic wave is 200 V/m. What is the wave amplitude at a nearby 0.20-mm-wide strip where 3000 photons are detected?

a. Starting with the expression ΔfΔt1for a wave packet, find an expression for the product ΔEΔtfor a photon.

b. Interpret your expression. What does it tell you?

c. The Bohr model of atomic quantization says that an atom in an excited state can jump to a lower-energy state by emitting a photon. The Bohr model says nothing about how long this process takes. You'll learn in Chapter 41 that the time any particular atom spends in the excited state before cmitting a photon is unprcdictablc, but the average lifetime Δtof many atoms can be determined. You can think of Δtas being the uncertainty in your knowledge of how long the atom spends in the excited state. A typical value is Δt10ns. Consider an atom that emits a photon with a 500nmwavelength as it jumps down from an excited state. What is the uncertainty in the energy of the photon? Give your answer in eV.

d. What is the fractional uncertainty ΔE/Ein the photon's energy?

3 shows the probability density for an electron that has passed through an experimental apparatus. What is the probability that the electron will land in a 0.010-mm-wide strip at (a) x = 0.000 mm, (b) x = 0.500 mm, (c) x = 1.000 mm, and (d) x = 2.000 mm?

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