These example sentences are selected automatically from various online news sources to reflect current usage of the word 'arachnophobia.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Heavy water (deuterium oxide (2H 2O) or D 2O) is a form of water that contains a larger than normal amount of the hydrogen isotope deuterium (2H or D, also known as heavy hydrogen), rather than the common hydrogen-1 isotope (1H or H, also called protium) that makes up most of the hydrogen in regular water.
In this 2 atoms of Hydrogen with 1 atom of Oxygen is present. In Heavy Water, instead of hydrogen deuterium (D) is present. Deuterium is an isotope of hydrogen with atomic mass = 2 So formula for Heavy Water becomes D2O. It is used in nuclear reactors as moderator.