It's important to approach discussions about science and religious beliefs with respect and open-mindedness. While Genesis 1:7 in the Bible does mention the existence of water, it's important to understand that religious texts often convey symbolic or metaphorical language to convey spiritual or philosophical truths.
In the context of scientific understanding, water is indeed composed of two hydrogen atoms and one oxygen atom, which combine through a chemical reaction to form a water molecule (H2O). This understanding is based on extensive scientific research and experimentation.
If you have concerns or questions about the relationship between science and religion, it would be more appropriate to have a respectful conversation with your teacher outside of the classroom setting. Remember, science and religious beliefs can coexist in different ways for different individuals, and it's essential to foster an environment of understanding and mutual respect.