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