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