A) the ratio of their masses is always the same. B) each element contributes an equal number of atoms. C) their masses are always equal. D) their volumes are always equal.
A) There is a dense, positively charged mass in the center of an atom. B) Alpha particles have a positive charge. 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) located in the space outside the nucleus. C) concentrated at multiple sites in an atom. D) spread evenly throughout an atom.
A) proton B) electron C) neutron
A) Protons, neutrons, and electrons all have about the same mass. B) An electron has far less mass then either a proton or a neutron. C) Unlike protons or neutrons, electrons have no mass. D) Neutrons have no charge and no mass.
A) the mass of the neutron B) the number of neutrons C) the charge on the electrons D) the number of protons
A) charge B) isotope C) mass number D) atomic number
A) mass number from atomic number B) atomic number from electron number C) atomic number from mass number D) isotope number from atomic number
A) like popcorn in a popper. B) like beach balls on water waves. C) like planets orbiting the sun. D) like balls rolling down a hill.
A) the precise location of electrons in an atom B) the mass of the electrons in the atom C) the number of electrons in an atom D) the most likely locations of electrons in an atom
A) they are usually gases B) the are extremely nonreactive C) they are located in the left-most column of the periodic table D) they form negative ions
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) atomic number C) atomic mass unit D) isotope number
A) the number of valence electrons in atoms of the element B) its atomic mass C) the ratio of protons to neutrons in atoms of the element D) how tightly atoms are packed in the element
A) their masses are identical B) they do not have the same number of protons C) They have the same mass number D) They are isotopes of oxygen
A) group to group B) row to row C) element to element D) column to column
A) helium, carbon, gold B) sodium, chromium, copper C) phosphorus, nitrogen, oxygen D) iodine, iron, nickel
A) the discovery of elements with predicted properties. B) the discovery of subatomic particles. C) the immediate acceptance by other scientists. D) the discovery of the nucleus.
A) three B) two C) four D) none
A) increases then decreases B) increases C) decreases D) stays the same
A) chlorine-35 atom B) neutron C) carbon-12 atom D) proton
A) -1 B) -2 C) 0 D) +1
A) 1 B) 0 C) 1/1840 D) 1/18
A) period B) mass C) chemical properties D) number of neutrons
A) losing or gaining protons B) changing from one period to another C) changing from lithium into fluorine D) losing or gaining electrons
A) one-twelfth the mass of a carbon-12 atom B) one-half the mass of a hydrogen 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) do not form compounds C) can conduct electric current only under certain conditions D) have large atomic masses but small atomic numbers
A) on the left B) in the middle C) on the right D) on the bottom
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) 80 B) 172 C) 79 D) 35
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