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