Identification of Elements from Given Reactions, Exercícios de Engenharia Elétrica

Baixe Identification of Elements from Given Reactions e outras Exercícios em PDF para Engenharia Elétrica, somente na Docsity! 29. None of the reactions given include a beta decay, so the number of protons, the number of neutrons, and the number of electrons are each conserved. Atomic numbers (numbers of protons and numbers of electrons) and molar masses (combined numbers of protons and neutrons) can be found in Appendix F of the text. (a) 1H has 1 proton, 1 electron, and 0 neutrons and 9Be has 4 protons, 4 electrons, and 9 − 4 = 5 neutrons, so X has 1 + 4 = 5 protons, 1 + 4 = 5 electrons, and 0 + 5 − 1 = 4 neutrons. One of the neutrons is freed in the reaction. X must be boron with a molar mass of 5 + 4 = 9 g/mol: 9B. (b) 12C has 6 protons, 6 electrons, and 12 − 6 = 6 neutrons and 1H has 1 proton, 1 electron, and 0 neutrons, so X has 6 + 1 = 7 protons, 6 + 1 = 7 electrons, and 6 + 0 = 6 neutrons. It must be nitrogen with a molar mass of 7 + 6 = 13 g/mol: 13N. (c) 15N has 7 protons, 7 electrons, and 15−7 = 8 neutrons; 1H has 1 proton, 1 electron, and 0 neutrons; and 4He has 2 protons, 2 electrons, and 4 − 2 = 2 neutrons; so X has 7 + 1 − 2 = 6 protons, 6 electrons, and 8 + 0 − 2 = 6 neutrons. It must be carbon with a molar mass of 6 + 6 = 12: 12C.