Why does a solid change to liquid when heat is added?
the spacing between particles decreases.
particles lose energy.
the spacing between particles increases.
the temperature decreases.

The spacing between particles increases.

Explanation:

Solids is the state of matter in which the atoms of the matter are closely packed by the strong forces.

When solid is converted to liquid, these force has to be broken in order for the conversion to take place.

Thus, on heating the molecules gain energy and posses kinetic energy and start vibrating and moving. This energy overcome the forces of attraction and the spacing of the atoms decreases and turns into liquid.

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