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