At show clearly how bonding occured in (cao)
Calcium
oxide

They both combine with The help of valency, which is the combining capacity of elements

Explanation:

I find it easier to understand valency as part of the Bhor’s model of an atom.

In his model, it was stated that electrons are spread around the nucleus in such a way that there are rings around the model. Each ring has a n value. So, k has 1, l has 2, m has 3 and n has 4...

what you need to know to find the number of electrons in each ring is to solve the formula 2n squared

Then, the valency is the 8 minus the number of electrons in the outermost shell. Remember that 8 is max number I;outer most shell. If you try it out for oxygen, you will get the value of 2 remaining, which can be gained if combined with calcium.

Hope it helps

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

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;