A) the ratio of their masses is always the same. B) their masses are always equal. C) their volumes are always equal. 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 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) 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) isotope B) atomic number C) mass number D) charge
A) atomic number from electron number B) mass number from atomic number C) atomic number from mass number D) isotope number from atomic number
A) like beach balls on water waves. B) like balls rolling down a hill. C) like popcorn in a popper. D) like planets orbiting the sun.
A) the number of electrons in an atom B) the most likely locations of electrons in an atom C) the precise location of electrons in an atom D) the mass of the electrons in the atom
A) they form negative ions B) the are extremely nonreactive C) they are located in the left-most column of the periodic table D) they are usually gases
A) mass of a substance B) electric charge of a substance C) amount of a substance D) volume 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) the ratio of protons to neutrons in atoms of the element C) its atomic mass D) how tightly atoms are packed in the element
A) They are isotopes of oxygen B) They have the same mass number C) their masses are identical D) they do not have the same number of protons
A) column to column B) row to row C) element to element D) group to group
A) phosphorus, nitrogen, oxygen B) helium, carbon, gold C) sodium, chromium, copper D) iodine, iron, nickel
A) the immediate acceptance by other scientists. B) the discovery of subatomic particles. C) the discovery of elements with predicted properties. D) the discovery of the nucleus.
A) none B) four C) two D) three
A) increases then decreases B) stays the same C) decreases D) increases
A) neutron B) carbon-12 atom C) chlorine-35 atom D) proton
A) +1 B) -2 C) -1 D) 0
A) 1 B) 1/1840 C) 1/18 D) 0
A) period B) mass C) number of neutrons D) chemical properties
A) losing or gaining electrons B) losing or gaining protons C) changing from lithium into fluorine D) changing from one period to another
A) one-fifteenth the mass of a nitrogen-15 atom B) one-fourth the mass of a lithium atom C) one-twelfth the mass of a carbon-12 atom D) one-half the mass of a hydrogen atom
A) they are highly reactive B) they can form compounds with bright colors C) They exist as single elements rather than molecules D) they are rare in nature
A) are extremely hard B) can conduct electric current only under certain conditions C) have large atomic masses but small atomic numbers 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) 35 D) 80
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