What is it called when a molecule uses energy to move across a semipermeable membrane?

a. diffusion
b. active transport
c. passive transport
d. osmosis

Active Transport

Explanation:

The movement of the particles across membrane needs energy. Energy is required in the condition where there is a movement of particles from a lower concentration to higher concentration.

It requires cellular energy for the movement of the particles. The larger molecules needs energy to move across concentration gradient.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.