Write electron configurations for the most stable ion formed by each of the elements Br, Cs, Sr, and O (when in stable ionic compounds).

Explanation:

Bromine belongs to group 7. It's most stable ion is the bromide, Br-.

Electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6

Caesium belongs to group 1. It's most stable ion is Cs+

Electronic configuration = 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6

Strontium belongs to group 2. It's most stable ion is the Sr2+

Electronic configuration = 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6

Oxygen belongs to group 6, it's most stable ion is O2-

Electronic configuration = 1s2 2s2 2p6

the answer is b & c i believe : )

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