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) Alpha particles have a positive charge. B) Negative and positive charges are spread evenly throughout an atom. C) There is a dense, positively charged mass in the center of an atom. D) Gold is not as dense as previously thought.
A) spread evenly throughout an atom. B) located in the space outside the nucleus. C) concentrated at multiple sites in an atom. D) concentrated in the center of an atom.
A) neutron B) electron C) proton
A) Protons, neutrons, and electrons all have about the same mass. B) Unlike protons or neutrons, electrons have no mass. C) Neutrons have no charge and no mass. D) An electron has far less mass then either a proton or a neutron.
A) the number of neutrons B) the charge on the electrons C) the number of protons D) the mass of the neutron
A) isotope B) atomic number C) charge D) mass number
A) atomic number from electron number B) atomic number from mass number C) mass number from atomic number D) isotope number from atomic number
A) like popcorn in a popper. B) like balls rolling down a hill. C) like beach balls on water waves. D) like planets orbiting the sun.
A) the number of electrons in an atom B) the most likely locations 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) electric charge of a substance B) mass of a substance C) volume of a substance D) amount of a substance
A) mass number B) atomic mass unit C) isotope number D) atomic number
A) how tightly atoms are packed in the element B) the number of valence electrons in atoms of the element C) its atomic mass D) the ratio of protons to neutrons in atoms of the element
A) they do not have the same number of protons B) They are isotopes of oxygen C) their masses are identical D) They have the same mass number
A) group to group B) element to element C) column to column D) row to row
A) phosphorus, nitrogen, oxygen B) helium, carbon, gold C) iodine, iron, nickel D) sodium, chromium, copper
A) the discovery of elements with predicted properties. B) the discovery of the nucleus. C) the immediate acceptance by other scientists. D) the discovery of subatomic particles.
A) four B) two C) three D) none
A) stays the same B) decreases C) increases D) increases then decreases
A) carbon-12 atom B) proton C) neutron D) chlorine-35 atom
A) 0 B) -1 C) +1 D) -2
A) 1/18 B) 1 C) 1/1840 D) 0
A) chemical properties B) mass C) number of neutrons D) period
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-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 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) can conduct electric current only under certain conditions B) are extremely hard C) have large atomic masses but small atomic numbers D) do not form compounds
A) on the right B) in the middle C) on the left D) on the bottom
A) one mole of a pure substance B) one gram of a pure substance C) one kilogram of a pure substance. D) one liter of a pure substance
A) 172 B) 35 C) 79 D) 80
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