What is the nature of water?
$\ce{H2O}$ is a both a neutral molecule and an amphoteric molecule &mdash; the two are not mutually exclusive terms. An amphoteric molecule is simply one that can act as either an acid or a base, while a neutral molecule is one in which the total number of protons is equal to the number of electrons, such that there is zero net charge. Water can act as a Brønsted acid (i.e., an $\ce{H+}$ donor), as per the following reaction:

$\ce{H2O + NH2- -&gt; OH- + NH3}$

However it can also act as a Brønsted base (i.e., an $\ce{H+}$ acceptor):

$\ce{H2O + HCl -&gt; H3O+ + Cl-}$

When proton transfer is involved, as in the Brønsted definition of acids and bases, the more precise term is amphiprotic. However, water can also act as both a Lewis acid (an electron pair acceptor) and Lewis base (an electron pair donor). Notably, as a Lewis base, it is not limited merely to proton abstraction, but can act as a nucleophile with any number of electrophilic molecules.