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) There is a dense, positively charged mass in the center of an atom. B) Negative and positive charges are spread evenly throughout an atom. C) Gold is not as dense as previously thought. D) Alpha particles have a positive charge.
A) concentrated in the center of an atom. B) concentrated at multiple sites in an atom. C) located in the space outside the nucleus. D) spread evenly throughout an atom.
A) electron B) neutron C) proton
A) An electron has far less mass then either a proton or a neutron. B) Unlike protons or neutrons, electrons have no mass. C) Neutrons have no charge and no mass. D) Protons, neutrons, and electrons all have about the same mass.
A) the mass of the neutron B) the number of protons C) the number of neutrons D) the charge on the electrons
A) charge B) mass number C) isotope D) atomic number
A) atomic number from mass number B) isotope number from atomic number C) mass number from atomic number D) atomic number from electron number
A) like beach balls on water waves. B) like planets orbiting the sun. C) like popcorn in a popper. D) like balls rolling down a hill.
A) the mass of the electrons in the atom B) the precise location of electrons in an atom C) the most likely locations of electrons in an atom D) the number of electrons in an atom
A) they are usually gases B) the are extremely nonreactive C) they are located in the left-most column of the periodic table D) they form negative ions
A) amount of a substance B) electric charge of a substance C) volume of a substance D) mass of a substance
A) mass number B) atomic number C) isotope number D) atomic mass unit
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 are isotopes of oxygen B) they do not have the same number of protons C) their masses are identical D) They have the same mass number
A) group to group B) column to column C) element to element D) row to row
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 elements with predicted properties. C) the discovery of the nucleus. D) the immediate acceptance by other scientists.
A) two B) three C) none D) four
A) increases then decreases B) increases C) decreases D) stays the same
A) proton B) carbon-12 atom C) chlorine-35 atom D) neutron
A) 0 B) -1 C) -2 D) +1
A) 1/1840 B) 1 C) 1/18 D) 0
A) period B) mass C) chemical properties D) number of neutrons
A) changing from one period to another B) losing or gaining electrons C) losing or gaining protons D) changing from lithium into fluorine
A) one-half the mass of a hydrogen atom B) one-fourth the mass of a lithium 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) can conduct electric current only under certain conditions D) have large atomic masses but small atomic numbers
A) on the left B) on the right C) in the middle D) on the bottom
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) 172 B) 79 C) 80 D) 35
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