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