Calculating Electrons in Silver Pin: 10g Mass, 47 e-/atom

In summary, to calculate the number of electrons in a small, electrically neutral silver pin with a mass of 10g, we can use dimensional analysis to find that there are approximately 2.62 x 10^24 electrons. To find how many electrons are added for every 10^9 electrons already present, we can divide the number of electrons in 1 mC (6.25 x 10^24) by the number of groups of 10^9 electrons in the silver pin (2.62 x 10^15), giving us 2.38 electrons added for every 10^9 electrons already present.
  • #1
jessedevin
66
0

Homework Statement



(a). Calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10g. Silver has 47 electrons per atom, and its molar mass is 107.87 g/mol.
(b). Imagine adding electrons to the pin until the negative charge has the very large value of 1.00 mC. How many electrons are added for every 10^9 electrons already present?

The Attempt at a Solution


I got the answers for both (a) and (b) (answers in back of book), but I still don't understand how to get (b). Heres my steps:

For (a), all I did was dimensional analysis to find the amount of electrons in 10 g of Ag, whic is about 2.62 x 10^24 e-. For part (b), I am confused, but what I found out how many electrons in 1 mC, which was 6.25 x 10^24 e-, and divided it by 2.62 x 10^24 e-, and I got 2.38 e- for every 10^9 electrons already present, but still this does not make sense to me. Can someone explain it to me or give me some helpful hints?
 
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  • #2
How many elementary electrical charges are there in one milliCoulomb?
 
  • #3
Carid said:
How many elementary electrical charges are there in one milliCoulomb?

6.25 x 10^24 e-... so what do I do with that?
 
  • #4
How many groups of 10^9 electrons are there in the silver pin?
 
  • #5
2.62 x 10^24 e-/10^9 e-=2.62 x 10^15
 
  • #6
So if I divide the number of electrical charges in one milliCoulomb by the number of groups of 10^9 electrons, won't that supply the answer to the question?
 
  • #7
why?
 
  • #8
It seems to me that's exactly what they are asking for...

How many electrons are added for every 10^9 electrons already present?
 

1. How many electrons are present in a 10g mass of silver pin?

The number of electrons in a silver pin with a mass of 10g can be calculated by using Avogadro's number, which is the number of particles in one mole of a substance. The molar mass of silver is 107.87 g/mol, and the atomic mass of silver is 107.87 g/mol. Therefore, one mole of silver contains 6.022 x 10^23 atoms. Since there is only one atom of silver per molecule, there are also 6.022 x 10^23 electrons per mole of silver. This means that a 10g mass of silver pin contains (6.022 x 10^23 electrons/mole)(10g/107.87 g) = 5.577 x 10^22 electrons.

2. How many electrons are in one atom of silver?

Each atom of silver contains 47 electrons. This can be determined by looking at the atomic number of silver, which is 47. The atomic number represents the number of protons and electrons in an atom of that element.

3. How is the number of electrons in a substance related to its mass?

The number of electrons in a substance is not directly related to its mass. The mass of a substance is determined by its atomic and/or molecular composition, while the number of electrons is determined by the number of atoms and their atomic structure. However, the mass of a substance can give an indication of the number of atoms present, which in turn can give an indication of the number of electrons.

4. Can the number of electrons in a silver pin change?

No, the number of electrons in a silver pin cannot change. The number of electrons in an atom is determined by the element's atomic number, which is a unique characteristic of that element. Therefore, the number of electrons in a silver pin will always be 47 per atom.

5. How does the number of electrons in a silver pin affect its properties?

The number of electrons in a silver pin does not directly affect its properties. The properties of silver are determined by its atomic and molecular structure, as well as external factors such as temperature and pressure. However, the number of electrons does play a role in the element's reactivity and bonding behavior with other elements.

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