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