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