Passive Transport: Simple Diffusion. Diffusion across a cell membrane is a type of passive transport, or transport across the cell membrane that does not require energy. ... Molecules that are hydrophobic, just like the hydrophobic region, can pass through the cell membrane by simple diffusion.
You can take the bus or carpool rather than drive with one or 2 people in one car
You can reduce the amount of electric you use by turning off lights, and shutting things that are "on" but you are not using them.
Use reusable water containers, filter your own water. Try not to use disposable items.
There are 4 atoms in ammonia.