Which statement is true about the substances present in a mixture? They always consist of the same element.

They are always in the same state of matter.

They can be separated by physical methods.

They can only be separated by chemical methods.

They can be separated by physical methods

Explanation:

A mixture contains 2 or more substances which are occurring together. Although they are occurring together, it is important to note that they are not chemically bonded.

What we are trying to say is that there is no chemical bond between the substances present in a union.

They are particularly bonded physically. Hence, to separate a mixture into its constituent parts, we surely need to employ the use of a physical method that works to separate these substances into their different parts.

The physical method selected is based on the properties of the materials present in the mix

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