A) their masses are always equal. B) their volumes are always equal. C) each element contributes an equal number of atoms. 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) Alpha particles have a positive charge. D) Gold is not as dense as previously thought.
A) spread evenly throughout an atom. B) concentrated at multiple sites in an atom. C) located in the space outside the nucleus. D) concentrated in the center of an atom.
A) electron B) neutron C) proton
A) Unlike protons or neutrons, electrons have 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) Neutrons have no charge and no mass.
A) the charge on the electrons B) the mass of the neutron C) the number of protons D) the number of neutrons
A) atomic number B) charge C) isotope D) mass number
A) isotope number from atomic number B) atomic number from mass number C) mass number from atomic number D) atomic number from electron number
A) like balls rolling down a hill. B) like popcorn in a popper. C) like beach balls on water waves. D) like planets orbiting the sun.
A) the precise location of electrons in an atom B) the mass of the electrons in the atom C) the number of electrons in an atom D) the most likely locations of electrons in an atom
A) they form negative ions B) they are located in the left-most column of the periodic table C) the are extremely nonreactive D) they are usually gases
A) mass of a substance B) volume of a substance C) amount of a substance D) electric charge of a substance
A) atomic number B) isotope number C) atomic mass unit D) mass number
A) the ratio of protons to neutrons in atoms of the element B) the number of valence electrons in atoms of the element C) its atomic mass D) how tightly atoms are packed in 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) row to row B) column to column C) element to element D) group to group
A) iodine, iron, nickel B) sodium, chromium, copper C) helium, carbon, gold D) phosphorus, nitrogen, oxygen
A) the discovery of elements with predicted properties. B) the discovery of the nucleus. C) the discovery of subatomic particles. D) the immediate acceptance by other scientists.
A) four B) three C) none D) two
A) stays the same B) decreases C) increases D) increases then decreases
A) carbon-12 atom B) neutron C) proton D) chlorine-35 atom
A) +1 B) 0 C) -2 D) -1
A) 1/1840 B) 0 C) 1/18 D) 1
A) period B) number of neutrons C) chemical properties D) mass
A) changing from lithium into fluorine B) losing or gaining protons C) losing or gaining electrons D) changing from one period to another
A) one-half the mass of a hydrogen atom B) one-fourth the mass of a lithium atom C) one-twelfth the mass of a carbon-12 atom D) one-fifteenth the mass of a nitrogen-15 atom
A) they can form compounds with bright colors B) They exist as single elements rather than molecules C) they are highly reactive D) they are rare in nature
A) are extremely hard B) do not form compounds C) can conduct electric current only under certain conditions D) have large atomic masses but small atomic numbers
A) in the middle B) on the right C) on the bottom D) on the left
A) one kilogram of a pure substance. B) one mole of a pure substance C) one gram of a pure substance D) one liter of a pure substance
A) 35 B) 79 C) 172 D) 80
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