Regrettably, an article about As2H4Se8 cannot be written because this substance does not exist in reality. When studying chemistry, we truly need to focus on noting, researching and identifying chemical substances based on their actual chemical structure, not simply by combining chemical elements.
On a related note, As, H, and Se are the symbols for the chemical elements Arsenic, Hydrogen, and Selenium. However, they cannot combine to form the substance As2H4Se8. Why is that? Because chemistry does not always obey the relatively simple combination of elements.
These elements need to be examined in the context of the chemical environment, temperature and pressure conditions, and their ability to interact with other elements. In this case, there is no information indicating that As, H, and Se can combine to form the substance As2H4Se8.
To better understand chemistry, we need to study and conduct experiments in the laboratory under the guidance of a teacher or a professional chemist. This helps us gain a deeper understanding of the structure, properties, and reactions of chemical substances.