The first knowledge of chemistry dates back to 3500 BC in Egypt and Mesopotamia. Chemistry was all about ceramics, dyes, or developed craftsmanship but not considerable skills because no one really understood the purpose. The basic idea of ​​elements or compounds was first formulated by the Greek philosopher between 500 and 300 BC when people believed that fire, water, earth and air combined to form all living and non-living things. At the beginning of Christianity, ancient Egyptian and Greek philosophers merged in the new ideas of science, starting with small experiments such as transforming metal into gold or imitating precious gems. Later people like Robert Boyle, Robert Hooke and John Mayow were only the few people who discovered specific things in history. Boyle was the founder of modern chemistry. He performed pressure experiments, using an air pump, and discovered volume and pressure in gases. Hooke gave the first rational explanation of combustion; as a combination with air. Mayow studied animal breathing. While they were all working together to understand the theory of combustion, two Germans named JJ Becher and G. E. Stahl introduced the false theory of phlogiston combustion, which came to a theory that all phlogiston substance is contained in all combustible bodies and then escapes when bodies burn. . The discovery of gases and the analysis of air as a mixture of gases occurred during the phlogiston period. Carbon dioxide was first invented by J. B van Helmont and then discovered by Joseph Black in 1754. The next element was hydrogen; Hydrogen was discovered by Boyle but was carefully studied by Henry Cavendish, which was called flammable air. Cavendish also discovered a hydra explosion...... middle of paper ......although wave radiation can cause cancer and other diseases, the benefits make it seem like nothing. There are many ways to prevent radiation from being harmful, so it's really not a big deal. The use of X-rays can kill bacteria that can cause many diseases other than food, so this is always a good thing for any invention. Without the help of some leading scientists, doctors and ordinary people, X-rays would never have been possible, so thanks to them you can find out if your arm is broken or it's just a bone bruise. From torn muscles to torn ligaments to pulled muscles, CT scans and MRIs (both done via X-rays) would never have been invented. Appreciate the objects you have, because without them you would never know where you would be. I think we can all agree that X-rays have been an important invention in our time.