Answer:
There are 3 significant figures in 675000
Explanation:
The rules for significant figures:
- Non zero digit (from 1 upward) are always significant
- Trailing zero are not significant
- but zero in the presence of decimal are significant
In this case, the trailing zeros are not significant thus only the first 3 non zero digit are significant.
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
.
"4" is the one coefficient of H+ among the following choices given in the question that <span>balances the atoms in the following half-reaction. The correct option among all the options that are given in the question is the fourth option or the last option. I hope that this is the answer that has actually helped you.</span>
The colour of copper sulphate solution is blue