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