There are two main ways in which molecules are transported into and out of cells - active transport and passive transport. which of the following statements is true of passive transport?

a.) energy, in the form of atp, is essential for passive transport.
b.) endocytosis and exocytosis are two forms of passive transport.
c.) molecules move up a concentration gradient during passive transport.
d.) carrier proteins are sometimes used during passive transport.

answer: if she breaths she a thho

explanation:

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.