Which of the following best describes a molecule?

Heres my Answer

Explanation: A molecule is defined as two or more atoms of the same element different element that are bound together. A molecule may be homonuclear, which means, it consists of atoms of one chemical element, as with oxygen (O2); or it may be heteronuclear, a chemical compound composed of more than one element, as with water (H2O).

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.

answer; both surfaces of the membrane are nonpermeable