Describe how molecules enter and leave a cell without the use of the cell’s energy

Through passive transport

Explanation:

Passive transport is the movement of molecules and ions across the cell membrane whith no use of energy, it usuale involves a difussion down its concentration gradient (a region where concentration changes) across a membrane, from higher to lower concentrations. Passive transport can happen by simple diffusion, facilitated diffusion, filtration, or osmosis.

I hope you find this information useful and interesting! Good luck!