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