Can you help me with this 19 points

21

Explanation:

To find the total atoms.

Multiply 3 *2 and you will get 6

Then multiply 3 * 5 and you will get 15.

You do this because there is 3 as a coefficient and is before the chemical compound. Furthermore, that means the same thing as a parenthesis.

Last of all, add 15 + 6 and you will get 21.

Therefore, there are a total of 21 atoms.

"the periodic table is arranged in order of atomic number."

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