June 2016 Chemistry Regents #72-74

Highlight to reveal answers and explanations

 

Questions 1-5 Questions 6-10 Questions 11-15 Questions 16-20 Questions 21-25 Questions 26-30 Questions 31-35 Questions 36-40 Questions 41-45 Questions 46-50

Question 51 Questions 52-53 Questions 54-55 Questions 56-58 Questions 59-60 Questions 61-62 Questions 63-65 Questions 66-69  Questions 70-71  Questions 72-74  Questions 75-77  Questions 78-81  Questions 82-85

 

Other Regents Exams

Question 72-74

 

 

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

 

Questions 1-5 Questions 6-10 Questions 11-15 Questions 16-20 Questions 21-25 Questions 26-30 Questions 31-35 Questions 36-40 Questions 41-45 Questions 46-50

Question 51 Questions 52-53 Questions 54-55 Questions 56-58 Questions 59-60 Questions 61-62 Questions 63-65 Questions 66-69  Questions 70-71  Questions 72-74  Questions 75-77  Questions 78-81  Questions 82-85
 

Back to Regents Exams

 

web stats analysis