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