A) their volumes are always equal. B) their masses are always equal. C) each element contributes an equal number of atoms. D) the ratio of their masses is always the same.
A) Gold is not as dense as previously thought. B) There is a dense, positively charged mass in the center of an atom. C) Negative and positive charges are spread evenly throughout an atom. D) Alpha particles have a positive charge.
A) concentrated in the center of an atom. B) located in the space outside the nucleus. C) spread evenly throughout an atom. D) concentrated at multiple sites in an atom.
A) neutron B) proton C) electron
A) An electron has far less mass then either a proton or a neutron. B) Unlike protons or neutrons, electrons have no mass. C) Protons, neutrons, and electrons all have about the same mass. D) Neutrons have no charge and no mass.
A) the number of protons B) the number of neutrons C) the charge on the electrons D) the mass of the neutron
A) mass number B) isotope C) atomic number D) charge
A) atomic number from mass number B) mass number from atomic number C) isotope number from atomic number D) atomic number from electron 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 most likely locations of electrons in an atom C) the number 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 located in the left-most column of the periodic table D) they are usually gases
A) volume of a substance B) electric charge of a substance C) amount of a substance D) mass of a substance
A) isotope number B) mass number C) atomic mass unit D) atomic number
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) They are isotopes of oxygen B) they do not have the same number of protons C) They have the same mass number D) their masses are identical
A) row to row B) group to group C) element to element D) column to column
A) sodium, chromium, copper B) iodine, iron, nickel C) phosphorus, nitrogen, oxygen D) helium, carbon, gold
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) three B) two C) four D) none
A) increases B) decreases C) stays the same D) increases then decreases
A) proton B) carbon-12 atom C) neutron D) chlorine-35 atom
A) 0 B) +1 C) -2 D) -1
A) 1/18 B) 0 C) 1 D) 1/1840
A) chemical properties B) mass C) period D) number of neutrons
A) losing or gaining protons B) changing from one period to another C) losing or gaining electrons D) changing from lithium into fluorine
A) one-twelfth the mass of a carbon-12 atom B) one-fourth the mass of a lithium atom C) one-half the mass of a hydrogen atom D) one-fifteenth the mass of a nitrogen-15 atom
A) They exist as single elements rather than molecules B) they can form compounds with bright colors C) they are rare in nature D) they are highly reactive
A) do not form compounds B) have large atomic masses but small atomic numbers C) can conduct electric current only under certain conditions D) are extremely hard
A) on the bottom B) in the middle C) on the left D) on the right
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) 79 B) 35 C) 172 D) 80
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