How many valence electrons does chlorine have ?

Chlorine has seven valence electrons.

Explanation: Chlorine has the atomic number of 17. The atomic number is an number of protons that present inside of the nucleus of an atom. All of the the atoms of an element have all of the same atomic number. Also, in every stable atom the number of electrons is always equal to the number of protons that it has.

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