How many significant digits are in 50.003010 nm?

Answer 1

Five, I believe. Zeros on either side of the decimal point are ignored, as are any zeros on the left end. Here is a guide which might help you: http://www.usca.edu/chemistry/genchem/sigfig.htm

Answer 2

There are eight.

For integers, you start at the first non-zero digit and count the number of digits to the last non-zero digit. However, this can lead to ambiguity. When given the number 5000, if you have no further information there is only ONE significant digit. However, if you know that the number is given to the nearest hundreds, it has TWO significant digits; if to the nearest ten it has THREE.

For numbers with an integer and fractional part, you count from the first non-zero digit to the last digit - even if the last digit is zero. Any trailing zero should signify the degree of rounding and so should only be present to indicate that the given number is accurate to that level of significance.

Therefore the number here lies in the range [50.0030095, 50.0030105), and all the digits from the first 5 to the last zero are significant : eight in all.

Even without the significance implied by the trailing zero, the number still has 7 significant digits: 50.00301. YOU simply CANNOT ignore the 0s on either side of the decimal point if there are non-zero digits further out.

Answer 3

8 of them.