Excess or deficit electrons.

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In summary, the problem involves a plastic sphere suspended between two parallel plates, and the question is how many excess or deficit electrons the sphere has. Using given values for mass, voltage, distance, and gravity, the magnitude of the charge on the sphere is calculated to be q=4.8x10^-20 C, which is positive. However, upon solving for the excess/deficit electrons, the result is 0.3, which is not an integer. After checking conversions and discovering an extra zero, the correct answer is found to be 3 excess/deficit electrons.
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Homework Statement



A small plastic sphere is suspended between two parallel plates like so: http://gyazo.com/0b5425a78b645d85da0b3475d6d71734

How many excess or deficit electrons does the sphere have?

Homework Equations



##m=2.60x10^{-15}kg##
##V=265.4V ##
##d=0.500cm=0.000500m=5.0x10^{-4}m##
##g=9.81m/s^2##

##q = \frac{mgd}{V}##

##q = Ne##
##e = 1.6x10^{-19}C##

The Attempt at a Solution



The charge on the sphere is clearly positive because it is suspended in mid air and I calculated the magnitude of the charge to be ##q=4.8x10^{-20}C##.

This confused me slightly. Solving for the excess/deficit electrons ##N = 0.3##.

How can the sphere have a fraction of a deficit of electrons? I thought ##N## could only be an integer.
 
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  • #2
Check your conversion of d to meters.
 
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  • #3
gneill said:
Check your conversion of d to meters.

Whoops, I forgot a zero there ##d = 5.00x10^{-4}m##.

This doesn't really change the answer though.

EDIT : Ohhh I have an extra zero -facepalm-

I got it now thanks!
 
  • #4
Zondrina said:
Whoops, I forgot a zero there ##d = 5.00x10^{-4}m##.

This doesn't really change the answer though.

EDIT : Ohhh I have an extra zero -facepalm-

I got it now thanks!

:smile:
 
  • #5


It is possible for the sphere to have a fraction of a deficit of electrons because the charge of an electron is very small compared to the total charge of the sphere. This means that even a small change in the number of electrons can result in a significant change in the overall charge of the sphere. Additionally, the calculation of excess or deficit electrons is based on an idealized model and may not accurately reflect the actual number of electrons present in the sphere. Other factors such as air currents, temperature, and surface imperfections can also affect the charge distribution on the sphere. Therefore, it is important to consider these factors when interpreting the results of this calculation.
 

1. What are excess or deficit electrons?

Excess or deficit electrons refer to the number of electrons present in an atom or molecule. It is a measure of the overall charge of the atom or molecule, with excess electrons indicating a negative charge and deficit electrons indicating a positive charge.

2. How do excess or deficit electrons affect chemical reactions?

The presence of excess or deficit electrons can significantly impact the reactivity of atoms and molecules. Excess electrons can make a molecule more reactive by providing an extra negative charge, while deficit electrons can make a molecule less reactive by reducing its overall negative charge.

3. What causes an excess or deficit of electrons?

Excess or deficit electrons can be caused by a variety of factors, such as gaining or losing electrons through chemical reactions, exposure to radiation, or changes in temperature or pressure. In some cases, excess or deficit electrons can also be inherited from the atoms or molecules that make up a substance.

4. How can excess or deficit electrons be measured?

The presence of excess or deficit electrons can be measured using various techniques, such as electron microscopy, spectroscopy, or electrochemical methods. These methods allow scientists to determine the number of excess or deficit electrons present in a substance and how they are distributed within the substance.

5. Can excess or deficit electrons be controlled?

Yes, excess or deficit electrons can be controlled to some extent by manipulating the conditions of a substance. For example, changing the temperature or pressure can alter the number of excess or deficit electrons in a substance. Additionally, chemical reactions can be used to either add or remove electrons from a substance, helping to balance out any excess or deficit electrons present.

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