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