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) There is a dense, positively charged mass in the center of an atom. B) Gold is not as dense as previously thought. C) Alpha particles have a positive charge. 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) located in the space outside the nucleus. D) concentrated at multiple sites in an atom.
A) proton B) neutron C) electron
A) An electron has far less mass then either a proton or a neutron. B) Protons, neutrons, and electrons all have about the same mass. C) Neutrons have no charge and no mass. D) Unlike protons or neutrons, electrons have no mass.
A) the mass of the neutron B) the charge on the electrons C) the number of neutrons D) the number of protons
A) mass number B) atomic number C) isotope D) charge
A) atomic number from electron number B) isotope number from atomic number C) mass number from atomic number D) atomic number from mass number
A) like beach balls on water waves. B) like planets orbiting the sun. C) like popcorn in a popper. D) like balls rolling down a hill.
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 form negative ions C) the are extremely nonreactive 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) 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) their masses are identical B) They are isotopes of oxygen C) They have the same mass number D) they do not have the same number of protons
A) column to column B) element to element C) group to group D) row to row
A) phosphorus, nitrogen, oxygen B) helium, carbon, gold C) sodium, chromium, copper D) iodine, iron, nickel
A) the discovery of the nucleus. B) the immediate acceptance by other scientists. C) the discovery of subatomic particles. D) the discovery of elements with predicted properties.
A) three B) none C) two D) four
A) increases B) decreases C) increases then decreases D) stays the same
A) neutron B) carbon-12 atom C) chlorine-35 atom D) proton
A) -2 B) -1 C) 0 D) +1
A) 1 B) 1/18 C) 0 D) 1/1840
A) period B) number of neutrons C) chemical properties D) mass
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-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 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) can conduct electric current only under certain conditions B) do not form compounds C) have large atomic masses but small atomic numbers D) are extremely hard
A) on the left B) on the right C) on the bottom D) in the middle
A) one gram of a pure substance B) one mole of a pure substance C) one liter of a pure substance D) one kilogram of a pure substance.
A) 35 B) 172 C) 79 D) 80
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