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