A) each element contributes an equal number of atoms. B) their volumes are always equal. C) the ratio of their masses is always the same. D) their masses are always equal.
A) Gold is not as dense as previously thought. B) Alpha particles have a positive charge. C) Negative and positive charges are spread evenly throughout an atom. D) There is a dense, positively charged mass in the center of an atom.
A) concentrated in the center of an atom. B) spread evenly throughout an atom. C) located in the space outside the nucleus. D) concentrated at multiple sites in an atom.
A) neutron B) proton C) electron
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 protons B) the charge on the electrons C) the number of neutrons D) the mass of the neutron
A) charge B) atomic number C) mass number D) isotope
A) isotope number from atomic number B) mass number from atomic number C) atomic number from mass number D) atomic number from electron 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 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) the are extremely nonreactive B) they are located in the left-most column of the periodic table C) they form negative ions D) they are usually gases
A) volume of a substance B) electric charge of a substance C) amount of a substance D) mass of a substance
A) atomic mass unit B) mass number C) isotope number D) atomic number
A) how tightly atoms are packed in the element B) its atomic mass C) the number of valence electrons in atoms of the element D) the ratio of protons to neutrons in atoms of the element
A) they do not have the same number of protons B) They are isotopes of oxygen C) their masses are identical D) They have the same mass number
A) row to row B) group to group C) element to element D) column to column
A) phosphorus, nitrogen, oxygen B) sodium, chromium, copper C) iodine, iron, nickel D) helium, carbon, gold
A) the discovery of subatomic particles. B) the immediate acceptance by other scientists. C) the discovery of elements with predicted properties. D) the discovery of the nucleus.
A) four B) none C) two D) three
A) increases B) stays the same C) decreases D) increases then decreases
A) carbon-12 atom B) proton C) chlorine-35 atom D) neutron
A) -2 B) -1 C) 0 D) +1
A) 0 B) 1/1840 C) 1 D) 1/18
A) period B) number of neutrons C) mass D) chemical properties
A) losing or gaining electrons B) changing from one period to another C) losing or gaining protons D) changing from lithium into fluorine
A) one-fourth the mass of a lithium atom B) one-twelfth the mass of a carbon-12 atom C) one-fifteenth the mass of a nitrogen-15 atom D) one-half the mass of a hydrogen atom
A) they can form compounds with bright colors B) they are highly reactive C) They exist as single elements rather than molecules D) they are rare in nature
A) are extremely hard B) can conduct electric current only under certain conditions C) do not form compounds D) have large atomic masses but small atomic numbers
A) on the bottom B) on the right C) on the left D) in the middle
A) one liter of a pure substance B) one gram of a pure substance C) one kilogram of a pure substance. D) one mole of a pure substance
A) 35 B) 172 C) 80 D) 79
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