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