A) their volumes are always equal. B) each element contributes an equal number of atoms. C) the ratio of their masses is always the same. D) their masses are always equal.
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) located in the space outside the nucleus. B) spread evenly throughout an atom. C) concentrated in the center of an atom. 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 mass of the neutron C) the charge on the electrons D) the number of neutrons
A) charge B) atomic number C) isotope D) mass number
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 balls rolling down a hill. B) like planets orbiting the sun. C) like beach balls on water waves. D) like popcorn in a popper.
A) the mass of the electrons in the atom B) the number of electrons in an atom C) the precise location of electrons in an atom D) the most likely locations of electrons in an atom
A) the are extremely nonreactive B) they are located in the left-most column of the periodic table C) they form negative ions D) they are usually gases
A) electric charge of a substance B) volume of a substance C) amount of a substance D) mass of a substance
A) mass number B) atomic number C) atomic mass unit D) isotope number
A) its atomic mass B) the number of valence electrons in atoms of the element C) the ratio of protons to neutrons in atoms of the element D) how tightly atoms are packed in the element
A) their masses are identical B) They have the same mass number C) they do not have the same number of protons D) They are isotopes of oxygen
A) group to group B) row to row C) element to element D) column to column
A) sodium, chromium, copper B) phosphorus, nitrogen, oxygen C) iodine, iron, nickel D) helium, carbon, gold
A) the immediate acceptance by other scientists. B) the discovery of the nucleus. C) the discovery of subatomic particles. D) the discovery of elements with predicted properties.
A) none B) three C) two D) four
A) increases then decreases B) stays the same C) decreases D) increases
A) neutron B) chlorine-35 atom C) proton D) carbon-12 atom
A) -1 B) 0 C) +1 D) -2
A) 1 B) 1/1840 C) 1/18 D) 0
A) mass B) number of neutrons C) period D) chemical properties
A) losing or gaining electrons B) changing from one period to another C) changing from lithium into fluorine D) losing or gaining protons
A) one-fourth the mass of a lithium atom B) one-half the mass of a hydrogen 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 can form compounds with bright colors D) They exist as single elements rather than molecules
A) can conduct electric current only under certain conditions B) are extremely hard C) do not form compounds D) have large atomic masses but small atomic numbers
A) on the left B) in the middle C) on the right D) on the bottom
A) one liter of a pure substance B) one kilogram of a pure substance. C) one gram of a pure substance D) one mole of a pure substance
A) 79 B) 80 C) 35 D) 172
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