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