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The image shows a page from a textbook in Russian, focusing on water (H₂O) and its properties as a compound. Here are some key points: 1. **About Water**: It details that water is a compound made of hydrogen and oxygen. 2. **Elementary Composition**: It consists of two hydrogen atoms and one oxygen atom, forming H₂O. 3. **Physical and Chemical Properties**: It describes water's physical and chemical characteristics. 4. **Common Name**: The common name for H₂O is given as "water." 5. **Verification of Knowledge**: It provides a task for the reader to verify their knowledge, such as determining what H₂O represents and understanding the properties of water. Additionally, the text discusses the characteristics of oxygen and its concentration.