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