What was Darwin's famous trip on the H. M.S beagle?

In 1831, Charles Darwin received an astounding invitation: to join the HMS Beagle as ship's naturalist for a trip around the world. For most of the next five years, the Beagle surveyed the coast of South America, leaving Darwin free to explore the continent and islands, including the Galápagos

Explanation:

In 1831, Charles Darwin received an astounding invitation: to join the HMS Beagle as ship's naturalist for a trip around the world. For most of the next five years, the Beagle surveyed the coast of South America, leaving Darwin free to explore the continent and islands, including the Galápagos.

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.

answer; both surfaces of the membrane are nonpermeable