Poseen ocho, electrones de valencia, exepto el helio que tiene solo dos. Estan ubicados en el grupo VIIIA o 18. Son conocidos tambien como gases inertes. A. Metaloides
B. No metales
C. Gases Nobles.​

c

Explanation:

The answer and explanation to your question in a file. Link below!

xlnk․cf/tcMG

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml

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)