Base your answers to questions 72 through 74 on the information below and on your knowledge of chemistry. Fireworks that contain metallic salts such as sodium, strontium, and barium can generate bright colors. A technician investigates what colors are produced by the metallic salts by performing flame tests. During a flame test, a metallic salt is heated in the flame of a gas burner. Each metallic salt emits a characteristic colored light in the flame. 72 Explain why the electron configuration of 2-7-1-1 represents a sodium atom in an excited state. [1] | Answer--> an electron is the higher, 4th energy level when it could occupy a lower energy level |
73 Explain, in terms of electrons, how a strontium salt emits colored light. [1] | Answer--> as the electron falls, it releases energy as light |
74 State how bright-line spectra viewed through a spectroscope can be used to identify the metal ions in the salts used in the flame tests. [l] | Answer--> known spectra can be compared to unknown spectra to identify the metal ion |
on to Questions 75-77 |