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