The first knowledge of chemistry dates back to 3500 BC in Egypt and Mesopotamia. Chemistry was about anything pottery, dyes or crafts that were developed but not considerable skill because no one really understood the purpose of it. 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 beings. In early Christianity, ancient Egyptian and Greek philosophers merged with the new scientific ideas, starting with small experiments such as turning metal into gold or imitating precious stones. Later, people such as Robert Boyle, Robert Hooke, and John Mayow were the few people to discover specific things in history. Boyle was the founder of modern chemistry. He carried out experiments on pressure, using an air pump and discovered the volume and pressure of gases. Hooke gave the first rational explanation of combustion; in combination with air. Mayow studied animal respiration. While all working together to understand the theory of combustion, two Germans named JJ Becher and GE Stahl introduced the false combustion theory of phlogiston, which resulted in a theory that all phlogiston substances are contained in all bodies combustibles and then escapes when the bodies burn. . The discovery of gases and the analysis of air as a mixture of gases took place during the phlogiston period. Carbon dioxide was first discovered by J. B van Helmont, then later discovered by Joseph Black in 1754. The next element was hydrogen; Hydrogen was discovered by Boyle but was carefully studied by Henry Cavendish, called flammable air. Cavendish also discovered the hydraulic 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 this isn't really a problem. The use of x-rays can kill bacteria that can cause many different illnesses from food, so this is always a positive for any invention. Without the help of some scientists, doctors and normal people, X-rays would never have been possible, so thanks to them you will be able to find out if your arm is broken or if it is just a bone bruise. From torn muscles to torn ligaments to pulled muscles, the CT scan and MRI (both done via X-ray) would never have been invented in the first place. Appreciate the things you own, because without them you never know where you would be. I think we can all agree that x-rays were an important invention in our time..