In an isolated system:
o
a. total (pe + ke) is unchanged.
ke remains the same.
o
c. matter flows in and out.
pe remains the same.

isolated system (plural isolated systems) (physics) A system that does not interact with its surroundings. Depending on context this may mean that its total energy and/or momentum stay constant.

Explanation:

An isolated system is a thermodynamic system that cannot exchange either energy or matter outside the boundaries of the system. ... The system may be enclosed such that neither energy nor mass may enter or exit.

is there both?

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.

where are the choice options?