To express the radius of a hydrogen atom, which is given as \(0.0000000529177\) millimeters, we can round this number to a more manageable approximation.
Looking at the digits, the number can be approximated as follows:
- The first significant digit is \(5\)
- The next significant digit is \(2\)
- Since the digits \(9\), \(1\), and \(7\) are less than \(5\), we do not round up.
Thus, rounding \(0.0000000529177\) gives us approximately \(0.00000005\).
So, the best choice for approximation is:
0.00000005