A) their volumes are always equal. B) each element contributes an equal number of atoms. C) the ratio of their masses is always the same. D) their masses are always equal.
A) Gold is not as dense as previously thought. B) Negative and positive charges are spread evenly throughout an atom. C) There is a dense, positively charged mass in the center of an atom. D) Alpha particles have a positive charge.
A) spread evenly throughout an atom. B) located in the space outside the nucleus. C) concentrated at multiple sites in an atom. D) concentrated in the center of an atom.
A) electron B) neutron C) proton
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 number of neutrons B) the charge on the electrons C) the mass of the neutron D) the number of protons
A) mass number B) charge C) atomic number D) isotope
A) atomic number from electron number B) mass number from atomic number C) isotope number from atomic number D) atomic number from mass 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 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) electric charge of a substance B) amount of a substance C) mass of a substance D) volume of a substance
A) mass number B) atomic number C) isotope number D) atomic mass unit
A) its atomic mass B) the number of valence electrons in atoms of the element C) how tightly atoms are packed in the element D) the ratio of protons to neutrons in atoms of the element
A) their masses are identical B) they do not have the same number of protons C) They have the same mass number D) They are isotopes of oxygen
A) row to row B) group to group C) element to element D) column to column
A) iodine, iron, nickel B) helium, carbon, gold C) sodium, chromium, copper D) phosphorus, nitrogen, oxygen
A) the immediate acceptance by other scientists. B) the discovery of subatomic particles. C) the discovery of elements with predicted properties. D) the discovery of the nucleus.
A) four B) none C) two D) three
A) increases B) stays the same C) increases then decreases D) decreases
A) proton B) neutron C) carbon-12 atom D) chlorine-35 atom
A) -2 B) -1 C) 0 D) +1
A) 1 B) 0 C) 1/1840 D) 1/18
A) chemical properties B) period C) number of neutrons D) mass
A) losing or gaining electrons B) losing or gaining protons C) changing from one period to another D) changing from lithium into fluorine
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 can form compounds with bright colors B) They exist as single elements rather than molecules C) they are highly reactive D) they are rare in nature
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 right B) on the left C) on the bottom D) in the middle
A) one liter of a pure substance B) one kilogram of a pure substance. C) one mole of a pure substance D) one gram of a pure substance
A) 79 B) 172 C) 35 D) 80
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