Question

1.What one factor identifies an atom as a specific element? . . Choices: the number of protons. . the atomic mass. . the number of neutrons. . the mass number. . . . 2.An atom of fluorine has an atomic number of 9 and an atomic mass of 19. The atom contains . . Choices: 19 protons, 19 electrons, and 9 neutrons. . 19 protons, 10 electrons, and 9 neutrons. . 9 protons, 10 electrons, and 10 neutrons. . 9 protons, 9 electrons, and 10 neutrons . . . 3.Experiments with cathode ray tubes led to a new model of the atom, sometimes called the \"plum pudding\" model, because of the discovery of the . Choices:. electron. . nucleus neutron. . proton.

Answer 1

Question 1. What one factor identifies an atom as a specific element? Answer: the number of protons. Remember that the atoms of a same element have the same number of protons, and the atoms of different elements cannot have the same number of protons. That permits to order the elements according to the atomic number (number of protons) in the periodic table. Question 2.An atom of fluorine has an atomic number of 9 and an atomic mass of 19. The atom contains Answer: 9 protons, 9 electrons, and 10 neutrons : because the atomic number is the number of protons, the number of electrons must be equal to the number of protons (because the atom is neutral), and the mass number is the number or protons plus the number of neutrons: 9 protons + 10 neutrons = 19 mass number (atomic mass). Question 33.Experiments with cathode ray tubes led to a new model of the atom, sometimes called the \"plum pudding\" model, because of the discovery of the . Answer. electron ... when electron was discovered JJ Thompson proposed the plum pudding model, in which the atom was a solid positively charged sphere with electrons distributed inside it.