A) the ratio of their masses is always the same. B) their volumes are always equal. C) their masses are always equal. D) each element contributes an equal number of atoms.
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) Alpha particles have a positive charge. 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) proton B) neutron C) electron
A) Unlike protons or neutrons, electrons have no mass. B) An electron has far less mass then either a proton or a neutron. C) Protons, neutrons, and electrons all have about the same mass. D) Neutrons have no charge and no mass.
A) the charge on the electrons B) the number of protons C) the mass of the neutron D) the number of neutrons
A) atomic number B) charge C) mass number D) isotope
A) atomic number from electron number B) isotope number from atomic number C) mass 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 popcorn in a popper. D) like planets orbiting the sun.
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 are usually gases B) they form negative ions C) they are located in the left-most column of the periodic table D) the are extremely nonreactive
A) volume of a substance B) mass of a substance C) amount of a substance D) electric charge of a substance
A) mass number B) atomic mass unit C) atomic number D) isotope number
A) the number of valence electrons in atoms of the element B) its atomic mass C) the ratio of protons to neutrons in atoms of the element D) how tightly atoms are packed in the element
A) They are isotopes of oxygen B) They have the same mass number C) their masses are identical D) they do not have the same number of protons
A) group to group B) element to element C) column to column D) row to row
A) iodine, iron, nickel B) helium, carbon, gold C) phosphorus, nitrogen, oxygen D) sodium, chromium, copper
A) the discovery of elements with predicted properties. B) the immediate acceptance by other scientists. C) the discovery of the nucleus. D) the discovery of subatomic particles.
A) four B) three C) none D) two
A) decreases B) increases C) increases then decreases D) stays the same
A) proton B) carbon-12 atom C) neutron D) chlorine-35 atom
A) -2 B) -1 C) +1 D) 0
A) 1/18 B) 0 C) 1 D) 1/1840
A) period B) number of neutrons C) chemical properties D) mass
A) losing or gaining protons B) changing from one period to another C) changing from lithium into fluorine D) losing or gaining electrons
A) one-half the mass of a hydrogen atom B) one-twelfth the mass of a carbon-12 atom C) one-fifteenth the mass of a nitrogen-15 atom D) one-fourth the mass of a lithium atom
A) they are highly reactive B) They exist as single elements rather than molecules C) they can form compounds with bright colors D) they are rare in nature
A) are extremely hard B) can conduct electric current only under certain conditions C) have large atomic masses but small atomic numbers D) do not form compounds
A) on the bottom B) on the right C) on the left D) in the middle
A) one kilogram of a pure substance. B) one mole of a pure substance C) one liter of a pure substance D) one gram of a pure substance
A) 35 B) 172 C) 80 D) 79
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