which statement is true about the four atoms shown in figures a, b, c, and d?
a. a and c are different elements, while d is an isotope of c.
b. b and d are different elements, while a is an isotope of d.
c. a and b are different elements, while c is an isotope of b.
d. c and d are different elements, while b is an isotope of c.

I think that the answer is A.

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