1) What is the mass and charge of a proton? a) 1 amu, positive b) 1 amu, neutral c) 1 g, positive d) 1 g, neutral 2) Which statement describes a concept included in the wave-mechanical model of the atom? a) Protons, neutrons, and electrons are located in the nucleus. b) Electrons orbit the nucleus in shells at fixed distances c) Atoms are hard, indivisible spheres. d) Electrons are located in regions called orbitals 3) Which statement describes the earliest model of the atom? a) An atom is an indivisible hard sphere. b) An atom has a small, dense nucleus. c) Electrons are negative particles in an atom. d) Electrons in an atom have wave-like properties. 4) What subatomic particles are found in the nucleus? a) protons and electrons b) protons and nucleons c) protons and neutrons 5) According to the electron-cloud model of the atom, an orbital is a a) circular path traveled by an electron around the nucleus b) spiral path traveled by an electron toward the nucleus c) region of the most probable proton location d) region of the most probable electron location 6) What can be determined if only the atomic number of an atom is known? a) the total number of neutrons in the atom, only b) the total number of protons in the atom, only c) the total number of protons and the total number of neutrons in the atom d) the total number of protons and the total number of electrons in the atom 7) The most common isotope of chromium has a mass number of 52, and an atomic number of 24. Which notation represents a different isotope of chromium? a) b) c) d) 8) Which particle has a mass that is approximately the same as the mass of a proton? a) electron b) neucleon c) neutron 9) An atom is electrically neutral because the a) number of protons equals the number of electrons b) number of protons equals the number of neutrons c) ratio of the number of neutrons to the number of electrons is 1:1 d) ratio of the number of neutrons to the number of protons is 2:1 10) Which two particles make up most of the mass of a hydrogen-2 atom? a) electron and neutron b) electron and proton c) proton and neutron d) proton and positron 11) Experimental evidence indicates that the nucleus of an atom a) has a negative charge b) contains most of the mass of the atom c) has no charge d) contains a small percentage of the mass of the atom 12) Compared to the entire atom, the nucleus of the atom is a) larger and contains little of the atom's mass b) smaller and contains little of the atom's mass c) smaller and contains most of the atom's mass d) larger and contains most of the atom's mass 13) Which particle has the least mass? a) a neutron b) a proton c) an electron d) a neucleon 14) Which of die following statements best describes an electron? a) It has a smaller mass than a proton and a positive charge. b) It has a greater mass than a proton and a positive charge. c) It has a greater mass than a proton and a negative charge d) It has a smaller mass than a proton and a negative charge. 15) What particle has a mass of approximately one atomic mass unit and a unit positive charge? a) a neutron b) a neucleon c) a proton d) an electron 16) What particle is electrically neutral? a) a neutron b) a neucleon c) a proton d) an electron 17) Which two particles have approximately the same mass? a) neutron and electron b) neutron and deuteron c) proton and electron d) proton and neutron 18) What is the nuclear charge of an atom with a mass of 23 and an atomic number of 11 ? a) 34+ b) 23+ c) 12+ d) 11+ 19) Compared to an atom of C-12, an atom of C-14 has a) fewer protons b) more neutrons c) more protons d) fewer neutron 20) The atomic mass of an element is defined as the weighted average mass of that elements a) least abundant isotope b) most abundant isotope c) naturally occurring isotopes d) radioactive isotopes

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