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: :
(1) What is the symbol of group 2?
(2) What is the symbol of group 1?
(3) What is the symbol of group 18?
(4) What is the symbol of group 18?
(5) What is the symbol of group 15?
(6) What is the symbol of group 16?
(7) What is the symbol of group 13?
(8) What is the symbol of group 17?
(9) What is the symbol of group 2?
(10) What is the symbol of group 3?