What are 2 reasons molecules cannot pass easily through the cell membrane? What part of the cell membrane helps them get through?

The cell membrane's main trait is its selective permeability, which means that it allows some substances to cross it easily, but not others. Small molecules that are nonpolar (have no charge) can cross the membrane easily through diffusion, but ions (charged molecules) and larger molecules typically cannot. A concentration gradient is a just a region of space over which the concentration of a substance changes, and substances will naturally move down their gradients, from an area of higher to an area of lower concentration.

In cells, some molecules can move down their concentration gradients by crossing the lipid portion of the membrane directly, while others must pass through membrane proteins in a process called facilitated diffusion.

Explanation:

there are your two reasons molecules cannot pass easily through the cell membrane and what part of the cell membrane helps them get through is concentration gradient

the volume of fluid displaced would equal the volume of the gas. use a gas syringe - this is a laboratory instrument that can be used to withdraw a certain volume of gas from a closed system or to measure the volume of gas from a chemical reaction.

d: the voltage of the secondary coil is less than that of the primary coil.

im not suree sorry if wrong