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