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) Gold is not as dense as previously thought. B) There is a dense, positively charged mass in the center of an atom. C) Negative and positive charges are spread evenly throughout an atom. D) Alpha particles have a positive charge.
A) spread evenly throughout an atom. B) concentrated at multiple sites in an atom. C) concentrated in the center of an atom. D) located in the space outside the nucleus.
A) proton B) electron C) neutron
A) Unlike protons or neutrons, electrons have no mass. B) An electron has far less mass then either a proton or a neutron. C) Neutrons have no charge and no mass. D) Protons, neutrons, and electrons all have about the same mass.
A) the mass of the neutron B) the number of neutrons C) the charge on the electrons D) the number of protons
A) isotope B) charge C) atomic number D) mass number
A) isotope number from atomic number B) atomic number from mass 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 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) they are located in the left-most column of the periodic table B) the are extremely nonreactive C) they are usually gases D) they form negative ions
A) mass of a substance B) electric charge of a substance C) amount of a substance D) volume of a substance
A) mass number B) atomic mass unit C) atomic number D) isotope number
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) their masses are identical C) they do not have the same number of protons D) They have the same mass number
A) column to column B) element to element C) row to row D) group to group
A) sodium, chromium, copper B) helium, carbon, gold C) iodine, iron, nickel D) phosphorus, nitrogen, oxygen
A) the discovery of subatomic particles. B) the discovery of elements with predicted properties. C) the discovery of the nucleus. D) the immediate acceptance by other scientists.
A) two B) four C) three D) none
A) decreases B) increases C) increases then decreases D) stays the same
A) proton B) chlorine-35 atom C) carbon-12 atom D) neutron
A) -2 B) +1 C) -1 D) 0
A) 0 B) 1/18 C) 1/1840 D) 1
A) period B) chemical properties C) mass D) number of neutrons
A) losing or gaining electrons B) changing from lithium into fluorine C) losing or gaining protons D) changing from one period to another
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 exist as single elements rather than molecules B) they are highly reactive C) they are rare in nature D) they can form compounds with bright colors
A) have large atomic masses but small atomic numbers B) do not form compounds C) are extremely hard D) can conduct electric current only under certain conditions
A) in the middle B) on the right C) on the bottom D) on the left
A) one gram of a pure substance B) one liter of a pure substance C) one kilogram of a pure substance. D) one mole of a pure substance
A) 172 B) 35 C) 80 D) 79
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