A boiling pot of soup with a lid on it to keep in the energy is what type of system? open
closed
isolated
none of the above

In a closed system, only energy can be exchanged between the system and the surroundings. In the same example of boiling a pot of water, putting the lid on the system changes it from open to closed. This is because when the lid is on the pot, matter can no longer escape.

Explanation:

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation: