A) the ratio of their masses is always the same. B) their masses are always equal. C) each element contributes an equal number of atoms. D) their volumes are always equal.
A) Gold is not as dense as previously thought. B) There is a dense, positively charged mass in the center of an atom. C) Alpha particles have a positive charge. D) Negative and positive charges are spread evenly throughout an atom.
A) concentrated in the center of an atom. B) concentrated at multiple sites in an atom. C) spread evenly throughout an atom. D) located in the space outside the nucleus.
A) electron B) neutron C) proton
A) Neutrons have no charge and no mass. B) Unlike protons or neutrons, electrons have no mass. C) An electron has far less mass then either a proton or a neutron. D) Protons, neutrons, and electrons all have about the same mass.
A) the mass of the neutron B) the number of protons C) the charge on the electrons D) the number of neutrons
A) charge B) mass number C) isotope D) atomic number
A) atomic number from electron number B) isotope number from atomic number C) atomic number from mass number D) mass number from atomic number
A) like planets orbiting the sun. B) like beach balls on water waves. C) like popcorn in a popper. D) like balls rolling down a hill.
A) the most likely locations of electrons in an atom B) the number of electrons in an atom C) the mass of the electrons in the atom D) the precise location of electrons in an atom
A) they form negative ions B) the are extremely nonreactive C) they are located in the left-most column of the periodic table D) they are usually gases
A) amount of a substance B) volume of a substance C) mass of a substance D) electric charge of a substance
A) isotope number B) atomic mass unit C) atomic number D) mass number
A) the ratio of protons to neutrons in atoms of the element B) the number of valence electrons in atoms of the element C) its atomic mass D) how tightly atoms are packed in the element
A) their masses are identical B) they do not have the same number of protons C) They are isotopes of oxygen D) They have the same mass number
A) group to group B) column to column C) row to row D) element to element
A) phosphorus, nitrogen, oxygen B) iodine, iron, nickel C) sodium, chromium, copper D) helium, carbon, gold
A) the discovery of subatomic particles. B) the discovery of the nucleus. C) the immediate acceptance by other scientists. D) the discovery of elements with predicted properties.
A) two B) four C) none D) three
A) increases B) increases then decreases C) decreases D) stays the same
A) carbon-12 atom B) chlorine-35 atom C) neutron D) proton
A) -2 B) +1 C) 0 D) -1
A) 0 B) 1/18 C) 1 D) 1/1840
A) period B) chemical properties C) number of neutrons D) mass
A) losing or gaining protons B) losing or gaining electrons C) changing from one period to another D) changing from lithium into fluorine
A) one-twelfth the mass of a carbon-12 atom B) one-half the mass of a hydrogen atom C) one-fourth the mass of a lithium atom D) one-fifteenth the mass of a nitrogen-15 atom
A) they can form compounds with bright colors B) They exist as single elements rather than molecules C) they are rare in nature D) they are highly reactive
A) are extremely hard B) have large atomic masses but small atomic numbers C) can conduct electric current only under certain conditions D) do not form compounds
A) on the left B) on the bottom C) on the right D) in the middle
A) one kilogram of a pure substance. B) one mole of a pure substance C) one gram of a pure substance D) one liter of a pure substance
A) 80 B) 172 C) 79 D) 35
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