A) each element contributes an equal number of atoms. B) their masses are always equal. C) their volumes are always equal. D) the ratio of their masses is always the same.
A) There is a dense, positively charged mass in the center of an atom. B) Negative and positive charges are spread evenly throughout an atom. C) Gold is not as dense as previously thought. D) Alpha particles have a positive charge.
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) proton B) electron C) neutron
A) Neutrons have no charge and no mass. B) Protons, neutrons, and electrons all have about the same mass. C) An electron has far less mass then either a proton or a neutron. D) Unlike protons or neutrons, electrons have no mass.
A) the charge on the electrons B) the mass of the neutron C) the number of neutrons D) the number of protons
A) atomic number B) charge C) mass number D) isotope
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 popcorn in a popper. C) like planets orbiting the sun. D) like beach balls on water waves.
A) the mass of the electrons in the atom B) the precise location of electrons in an atom C) the most likely locations of electrons in an atom D) the number of electrons in an atom
A) they are usually gases B) they form negative ions C) the are extremely nonreactive D) they are located in the left-most column of the periodic table
A) mass of a substance B) amount of a substance C) volume of a substance D) electric charge of a substance
A) atomic number B) mass number C) atomic mass unit D) isotope number
A) the ratio of protons to neutrons in atoms of the element B) how tightly atoms are packed in the element C) its atomic mass D) the number of valence electrons in atoms of the element
A) they do not have the same number of protons B) They are isotopes of oxygen C) They have the same mass number D) their masses are identical
A) column to column B) element to element C) row to row D) group to group
A) helium, carbon, gold B) phosphorus, nitrogen, oxygen C) sodium, chromium, copper D) iodine, iron, nickel
A) the immediate acceptance by other scientists. B) the discovery of the nucleus. C) the discovery of elements with predicted properties. D) the discovery of subatomic particles.
A) two B) none C) four D) three
A) stays the same B) increases then decreases C) decreases D) increases
A) chlorine-35 atom B) proton C) carbon-12 atom D) neutron
A) 0 B) -1 C) +1 D) -2
A) 1 B) 0 C) 1/1840 D) 1/18
A) period B) mass C) chemical properties D) number of neutrons
A) losing or gaining protons B) changing from one period to another C) losing or gaining electrons D) changing from lithium into fluorine
A) one-twelfth the mass of a carbon-12 atom B) one-fourth the mass of a lithium atom C) one-half the mass of a hydrogen atom D) one-fifteenth the mass of a nitrogen-15 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) 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 right B) on the left C) in the middle D) on the bottom
A) one kilogram of a pure substance. B) one gram of a pure substance C) one liter of a pure substance D) one mole of a pure substance
A) 80 B) 35 C) 79 D) 172
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