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) Gold is not as dense as previously thought. B) Negative and positive charges are spread evenly throughout an atom. C) Alpha particles have a positive charge. D) There is a dense, positively charged mass in the center of an atom.
A) concentrated in the center of an atom. B) spread evenly throughout an atom. C) located in the space outside the nucleus. D) concentrated at multiple sites in an atom.
A) electron B) proton C) neutron
A) Unlike protons or neutrons, electrons have no mass. B) Neutrons have no charge and no mass. C) An electron has far less mass then either a proton or a neutron. 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) isotope B) mass number C) charge D) atomic number
A) atomic number from mass number B) isotope number from atomic number C) atomic number from electron number D) mass number from atomic number
A) like planets orbiting the sun. B) like beach balls on water waves. C) like balls rolling down a hill. D) like popcorn in a popper.
A) the precise location of electrons in an atom B) the number of electrons in an atom C) the mass of the electrons in the atom D) the most likely locations of electrons in an atom
A) they form negative ions B) they are usually gases C) they are located in the left-most column of the periodic table D) the are extremely nonreactive
A) electric charge of a substance B) amount of a substance C) mass of a substance D) volume of a substance
A) mass number B) atomic mass unit C) isotope number D) atomic number
A) its atomic mass B) the ratio of protons to neutrons in atoms of the element C) how tightly atoms are packed in the element D) the number of valence electrons in atoms of the element
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 the nucleus. B) the immediate acceptance by other scientists. C) the discovery of subatomic particles. D) the discovery of elements with predicted properties.
A) none B) two C) four D) three
A) stays the same B) increases then decreases C) increases D) decreases
A) neutron B) carbon-12 atom C) chlorine-35 atom D) proton
A) +1 B) -2 C) -1 D) 0
A) 1/18 B) 1/1840 C) 1 D) 0
A) mass B) chemical properties C) number of neutrons D) period
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-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 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) are extremely hard D) do not form compounds
A) on the bottom B) on the left C) on the right D) in the middle
A) one mole of a pure substance B) one liter of a pure substance C) one gram of a pure substance D) one kilogram of a pure substance.
A) 172 B) 79 C) 80 D) 35
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