Why hydrophobic molecules can easily cross the plasma membrane?

Hydrophobic molecules can easily cross the plasma membrane because they are nonpolar and can easily dissolve in the lipid bilayer, which is primarily composed of phospholipids with hydrophobic tails. This compatibility allows them to pass through the membrane without requiring energy or specific transport proteins. As a result, small hydrophobic molecules, such as oxygen and carbon dioxide, can diffuse freely across the membrane, facilitating their movement in and out of the cell.