The element oxygen, represented by the symbol O, is classified as A. a mixture.
В. a pure substance.
C. a compound
D. a solution

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

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

a electronegativity decreases beacuse the size of nucleus is bigger.