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