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