Question

The mass of a sample weighed on an electronic balance that is sensitive to 0.3 mg is 1.2300 g. the number of significant figures in this measurement is

Answer 1

The sensitivity of electronic balance is 0.3 mg

Converting 0.3 mg to g:

$0.3 mg * \frac{1g}{1000 mg} = 0.0003$g

So, the mass of a substance weighed on the balance can be measured accurately up to four decimal places.

Given the mass of sample is 1.2300 g. The number of significant figures in the measurement will be 5 because the balance can measure the mass of a sample accurately up to four decimal points, all the digits in the measurement will be significant.