If the average quarter weighs 5.67grams, how many atoms of nickel are in a quarter?
ie; 91.67%mass/copper 8.33%mass/nickel
I took 5.67x0.0833=.47g
.47gNi/58.6934=801 atoms nickel? is this right?
5.67 x 0.0833 = 0.47 g Ni is correct but you rounded too much. You are allowed three significant figures so I would use all of them and I get 0.472.
Then 0.472gNi/58.693 = 0.00804 is the right process but that added two on mine makes my answer a little higher. This is the right number but it is the number of MOLES Ni, not atoms.
Now remember that there are 6.022E23 atoms in a mole of Ni so
0.00804 x 6.22E23 = # atoms Ni.
Why 58.693
To determine the number of atoms of nickel in a quarter, you need to follow these steps:
1. Find the mass of nickel in the quarter:
- Multiply the average weight of a quarter (5.67 grams) by the percentage of mass attributed to nickel (8.33% or 0.0833).
- 5.67 grams x 0.0833 = 0.472011 grams
2. Convert the mass of nickel to moles:
- Divide the mass of nickel (0.472011 grams) by the molar mass of nickel (58.6934 g/mol).
- 0.472011 grams / 58.6934 g/mol = 0.008054 moles
3. Calculate the number of atoms in the given number of moles:
- Multiply the number of moles (0.008054) by Avogadro's number, which is approximately 6.022 x 10^23 atoms/mol.
- 0.008054 moles x 6.022 x 10^23 atoms/mol = 4.85 x 10^21 atoms
Therefore, there are approximately 4.85 x 10^21 atoms of nickel in a quarter.