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