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