Homework to be completed prior to 10/05/2014 Chemistry SAT class

1.      Wave–particle duality:

A theory that proposes that every elementary particle including electron exhibits the properties of not only particles, but also waves.

Watch vedio: DOUBLE SLIT EXPERIMENT:  https://www.youtube.com/watch?v=Q1YqgPAtzho

 2.      Single particle

The momentum of a particle is traditionally represented by the letter p. It is the product of two quantities, the mass (represented by the letter m) and velocity (v):

P = mv

Go to Princeton AP book, page 275, find above equation and the definition of p and m and v.

3.     Heisenberg’s uncertainty principle:

It tells us that it is impossible to simultaneously measure the position and momentum of a particle with infinite precision, i.e. (Δp((Δx) ≥ h/4π  

Heisenberg established this expression as the minimum amount of unavoidable momentum disturbance caused by any position measurement.  He refined his principle:

\Delta x \, \Delta p\gtrsim h\qquad\qquad\qquad (1)

Go to Princeton AP book, page 275, find the definition and value of of h (Planck’s constant) in the above equation.

This equation reveals that the more accurately a particle’s position is known, or the smaller Δx is, the less accurately the momentum of the particle Δp is known. Mathematically, this occurs because the smaller Δx becomes, the larger Δp must become in order to satisfy the inequality. However, the more accurately momentum is known the less accurately position is known. 

(In our everyday lives we virtually never come up against this limit).

You may see

 \Delta x\, \Delta p \ge \frac{\hbar}{2}

\hbar = {{h}\over{2\pi}} = 1.054\ 571\ 726(47)\times 10^{-34}\ \text{J⋅s} = 6.582\ 119\ 28(15)\times 10^{-16}\ \text{eV⋅s}.

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