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