According to one acid-base theory, a water molecule acts as a base when it accepts
(1) an h+ ion (3) a neutron
(2) an oh- ion (4) an electron

Answer : The correct option is, (1) an ion

Explanation :

According to the Bronsted-Lowry or acid-base concept, a substance is called as an acid if it can donate a proton and a substance is called as a base if it can accept a proton. And the substance may be a molecule or an ion.

When a water molecule acts as an acid then it can donate a proton or ion.

When a water molecule acts as a base then it can accepts a proton or ion.

Hence, the correct option is, (1) an ion

idk

explanation:

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.