The mass of piece of sterling silver jewelry is 33.24 g. It contains 92.5% silver Ag by mass. Since, sterling silver is an alloy of Ag-Cu thus, percentage of Cu will be:
% Cu=100-92.5=7.5%
Thus, mass of copper will be:
Molar mass of Cu is 63.546 g/mol, thus, number of moles of Cu can be calculated as follows:
Here, m is mass and M is molar mass.
Putting the values,
Now, in 1 mole of Cu there are 
thus, in 0.03923 mol, number of Cu atoms will be:
Thus, number of atoms of Cu will be
.
-30°C is more warmer than -30°F...!
<h2>How??</h2>
- Always Celsius is warmer than farheniet and also in coldness Celsius is colder than farheneit.
the answer is heat. while a car is in idol, the tailpipe gets very hot, (motorcycle, car, etc.) this also produces h20 which you can see dripping out of the tailpipe.
Causes carbon to move from one reservoir to another
The time taken by Carbon-14 to decay radioactively from 120g to 112.5g is 22,920 years.
<h3>How do we calculate the total time of decay?</h3>
Time required for the whole radioactive decay of any substance will be calculated by using the below link:
T = (n)(t), where
- t = half life time = 5730 years
- n = number of half life required for the decay
Initial mass of Carbon-14 = 120g
Final mass of Carbon-14 = 112.5g
Left mass = 120 - 112 = 7.5g
Number of required half life for this will be:
- 1: 120 → 60
- 2: 60 → 30
- 3: 30 → 15
- 4: 15 → 7.5
4 half lives are required, now on putting values we get
T = (4)(5730) = 22,920 years
Hence required time for the decay is 22,920 years.
To know more about radioactive decay, visit the below link:
brainly.com/question/24115447
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