A) their volumes are always equal. B) each element contributes an equal number of atoms. C) the ratio of their masses is always the same. D) their masses are always equal.
A) Negative and positive charges are spread evenly throughout an atom. B) Alpha particles have a positive charge. 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) concentrated at multiple sites in an atom. C) located in the space outside the nucleus. D) concentrated in the center of an atom.
A) neutron B) electron C) proton
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 number of protons B) the charge on the electrons C) the mass of the neutron D) the number of neutrons
A) isotope B) mass number C) atomic number D) charge
A) mass number from atomic number B) isotope number from atomic number C) atomic number from mass number D) atomic number from electron number
A) like planets orbiting the sun. B) like balls rolling down a hill. C) like beach balls on water waves. D) like popcorn in a popper.
A) the number of electrons in an atom B) the mass of the electrons in the atom C) the precise location of electrons in an atom D) the most likely locations of electrons in an atom
A) they are located in the left-most column of the periodic table B) the are extremely nonreactive C) they are usually gases D) they form negative ions
A) mass of a substance B) electric charge of a substance C) volume of a substance D) amount of a substance
A) mass number B) atomic number C) isotope number D) atomic mass unit
A) its atomic mass B) how tightly atoms are packed in the element C) the number of valence electrons in atoms of the element D) the ratio of protons to neutrons in atoms of the element
A) They are isotopes of oxygen B) their masses are identical C) they do not have the same number of protons D) They have the same mass number
A) element to element B) column to column C) group to group 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 immediate acceptance by other scientists. C) the discovery of subatomic particles. D) the discovery of the nucleus.
A) four B) three C) none D) two
A) decreases B) increases C) increases then decreases D) stays the same
A) chlorine-35 atom B) neutron C) proton D) carbon-12 atom
A) +1 B) 0 C) -1 D) -2
A) 1/1840 B) 1 C) 1/18 D) 0
A) chemical properties B) mass C) period D) number of neutrons
A) changing from lithium into fluorine B) losing or gaining protons C) losing or gaining electrons D) changing from one period to another
A) one-twelfth the mass of a carbon-12 atom B) one-half the mass of a hydrogen atom C) one-fifteenth the mass of a nitrogen-15 atom D) one-fourth the mass of a lithium atom
A) they are rare in nature B) they are highly reactive C) They exist as single elements rather than molecules 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) are extremely hard D) do not form compounds
A) on the left B) in the middle C) on the bottom D) on the right
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) 35 B) 80 C) 79 D) 172
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