A) their volumes are always equal. B) their masses are always equal. C) each element contributes an equal number of atoms. D) the ratio of their masses is always the same.
A) Gold is not as dense as previously thought. B) Alpha particles have a positive charge. C) There is a dense, positively charged mass in the center of an atom. D) Negative and positive charges are spread evenly throughout an atom.
A) concentrated in the center of an atom. B) located in the space outside the nucleus. C) spread evenly throughout an atom. D) concentrated at multiple sites in an atom.
A) electron B) neutron C) proton
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 neutrons B) the number of protons C) the charge on the electrons D) the mass of the neutron
A) charge B) mass number C) atomic number D) isotope
A) mass number from atomic number B) isotope number from atomic number C) atomic number from electron 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 mass of the electrons in the atom B) the most likely locations of electrons in an atom C) the precise location of electrons in an 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) electric charge of a substance B) amount of a substance C) mass of a substance D) volume of a substance
A) isotope number B) mass number C) atomic number D) atomic mass unit
A) the ratio of protons to neutrons in atoms of the element B) its atomic mass C) how tightly atoms are packed in the element D) the number of valence electrons in atoms of the element
A) They have the same mass number B) they do not have the same number of protons C) their masses are identical D) They are isotopes of oxygen
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 discovery of the nucleus. B) the discovery of elements with predicted properties. C) the discovery of subatomic particles. D) the immediate acceptance by other scientists.
A) none B) four C) two D) three
A) decreases B) increases then decreases C) stays the same D) increases
A) chlorine-35 atom B) carbon-12 atom C) neutron D) proton
A) -2 B) -1 C) 0 D) +1
A) 1/1840 B) 1/18 C) 1 D) 0
A) chemical properties B) mass C) number of neutrons D) period
A) losing or gaining electrons B) losing or gaining protons C) changing from one period to another D) changing from lithium into fluorine
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 rare in nature B) they can form compounds with bright colors C) they are highly reactive D) They exist as single elements rather than molecules
A) do not form compounds B) have large atomic masses but small atomic numbers C) can conduct electric current only under certain conditions D) are extremely hard
A) in the middle B) on the right C) on the bottom D) on the left
A) one liter of a pure substance B) one mole of a pure substance C) one gram of a pure substance D) one kilogram of a pure substance.
A) 35 B) 79 C) 80 D) 172
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