What is the solution to the problem to the correct number of significant figures (102,900/12)+(170•1.27)

As per as the Multiplication rules of the significant figures, whenever any numbers in the decimals forms are multiplied or divided then result in mentioned in such a way so that the significant figures after the decimal will be same as that in the given least condition.

102900/12 = 8575

170 × 1.27 = 215.9

∴ (102,900 ÷ 12) + (170 × 1.27) =  8575 + 215.9

= 8790.9

Now, As per as Above rules, answer in correct significant figures will be = 8791.

since electrons are negative the answer is neagtaive

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)