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