sample with masses 0.12g,1.8g, and 0.562g are mixed together the combind mass of the three samples expressed to the correct number of significant figures should be recorded as

2.5 g

Explanation:

Given data:

Masses of sample = 0.12 g, 1.8 g, 0.562 g

Combine mass of samples = ?

Solution:

When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places.

0.12 g + 1.8 g + 0.562 g

2.482 g

In given three measurements 1.8 has less number of significant figure after decimal point which is only one digit. Thus the final value must contain one digit after decimal.

we will round of 2.482 g.

2.5 g

because the next digit after 4 is 8 that's why we will round 4 to 5.