Pls help
7. What is the wavelength of X-rays having a frequency of 8.40 x 10^20 Hz?

What is the lowest number energy level where a d sublevel is found

Which of the following describes a compound? (hint: carbon and oxygen bo a. a piece of pure carbon, containing only carbon atoms b. oxygen gas surrounding a solid piece of carbon c. a substance made of two oxygen atoms for each carbon atom carbon and oxygen atoms mixed without being bonded together

Which terms are used to identify pure substances