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