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) There is a dense, positively charged mass in the center of an atom. B) Alpha particles have a positive charge. 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 in the center of an atom. C) concentrated at multiple sites in an atom. D) located in the space outside the nucleus.
A) neutron B) proton C) electron
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 neutrons D) the number of protons
A) isotope B) atomic number C) mass number D) charge
A) atomic number from mass number B) isotope number from atomic number C) atomic number from electron number D) mass number from atomic number
A) like balls rolling down a hill. B) like planets orbiting the sun. C) like popcorn in a popper. D) like beach balls on water waves.
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 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) amount of a substance B) mass of a substance C) electric charge of a substance D) volume of a substance
A) isotope number B) atomic number C) atomic mass unit D) mass number
A) the ratio of protons to neutrons in atoms of the element B) its atomic mass C) the number of valence electrons in atoms of the element D) how tightly atoms are packed in the element
A) They have the same mass number B) they do not have the same number of protons C) They are isotopes of oxygen D) their masses are identical
A) row to row B) column to column C) element to element D) group to group
A) sodium, chromium, copper B) iodine, iron, nickel C) helium, carbon, gold D) phosphorus, nitrogen, oxygen
A) the discovery of elements with predicted properties. B) the discovery of the nucleus. C) the discovery of subatomic particles. D) the immediate acceptance by other scientists.
A) four B) three C) two D) none
A) increases then decreases B) increases C) stays the same D) decreases
A) carbon-12 atom B) chlorine-35 atom C) proton D) neutron
A) +1 B) 0 C) -1 D) -2
A) 1/1840 B) 1/18 C) 0 D) 1
A) chemical properties B) mass C) period D) number of neutrons
A) losing or gaining electrons B) changing from lithium into fluorine C) changing from one period to another D) losing or gaining protons
A) one-twelfth the mass of a carbon-12 atom B) one-fourth the mass of a lithium atom C) one-half the mass of a hydrogen atom D) one-fifteenth the mass of a nitrogen-15 atom
A) they are rare in nature B) They exist as single elements rather than molecules C) they can form compounds with bright colors D) they are highly reactive
A) have large atomic masses but small atomic numbers B) do not form compounds C) can conduct electric current only under certain conditions D) are extremely hard
A) on the left B) on the right C) in the middle D) on the bottom
A) one liter of a pure substance B) one mole of a pure substance C) one kilogram of a pure substance. D) one gram of a pure substance
A) 35 B) 79 C) 80 D) 172
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