Isolated RNA molecules are generally less stable than DNA at physiological pH because RNA has a 2'-OH group on its ribose sugar whereas DNA has a 2'-H group. This 2'-OH group makes RNA more susceptible to hydrolysis than DNA. The 2'-OH group can participate in intramolecular and intermolecular interactions with the phosphate backbone, resulting in a partial negative charge that can become more acidic and facilitate the hydrolysis of the RNA backbone. Additionally, the 2'-OH group can create reactive intermediates that can cause RNA strand breaks. In contrast, DNA lacks this 2'-OH group, which allows it to be more stable under physiological conditions.