A) their volumes are always equal. B) their masses are always equal. C) each element contributes an equal number of atoms. D) the ratio of their masses is always the same.
A) Alpha particles have a positive charge. B) There is a dense, positively charged mass in the center of an atom. C) Negative and positive charges are spread evenly throughout an atom. D) Gold is not as dense as previously thought.
A) spread evenly throughout an atom. B) concentrated at multiple sites in an atom. C) concentrated in the center of an atom. D) located in the space outside the nucleus.
A) proton B) electron C) neutron
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 protons B) the charge on the electrons C) the number of neutrons D) the mass of the neutron
A) isotope B) atomic number C) mass number D) charge
A) atomic number from mass number B) atomic number from electron number C) isotope number from atomic number D) mass number from atomic number
A) like balls rolling down a hill. B) like popcorn in a popper. C) like beach balls on water waves. D) like planets orbiting the sun.
A) the precise location of electrons in an atom B) the mass of the electrons in the atom C) the most likely locations of electrons in an atom D) the number of electrons in an atom
A) they form negative ions B) they are located in the left-most column of the periodic table C) they are usually gases D) the are extremely nonreactive
A) mass of a substance B) volume of a substance C) electric charge of a substance D) amount of a substance
A) mass number B) isotope number C) atomic mass unit D) atomic number
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) They have the same mass number B) their masses are identical C) They are isotopes of oxygen D) they do not have the same number of protons
A) row to row B) group to group C) element to element D) column to column
A) sodium, chromium, copper B) phosphorus, nitrogen, oxygen C) helium, carbon, gold D) iodine, iron, nickel
A) the discovery of subatomic particles. B) the immediate acceptance by other scientists. C) the discovery of the nucleus. D) the discovery of elements with predicted properties.
A) none B) three C) four D) two
A) increases B) stays the same C) increases then decreases D) decreases
A) carbon-12 atom B) proton C) chlorine-35 atom D) neutron
A) +1 B) -2 C) 0 D) -1
A) 0 B) 1/1840 C) 1/18 D) 1
A) number of neutrons B) mass C) chemical properties D) period
A) losing or gaining protons B) changing from lithium into fluorine C) changing from one period to another D) losing or gaining electrons
A) one-fourth the mass of a lithium atom B) one-twelfth the mass of a carbon-12 atom C) one-half the mass of a hydrogen 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) can conduct electric current only under certain conditions B) are extremely hard C) do not form compounds D) have large atomic masses but small atomic numbers
A) in the middle B) on the left C) on the right D) on the bottom
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) 80 B) 172 C) 79 D) 35
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