A) the ratio of their masses is always the same. B) their masses are always equal. C) their volumes are always equal. D) each element contributes an equal number of atoms.
A) Alpha particles have a positive charge. B) Negative and positive charges are spread evenly throughout an atom. C) Gold is not as dense as previously thought. D) There is a dense, positively charged mass in the center of an atom.
A) located in the space outside the nucleus. B) spread evenly throughout an atom. C) concentrated at multiple sites in an atom. D) concentrated in the center of an atom.
A) proton B) electron C) neutron
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 charge on the electrons B) the number of neutrons C) the number of protons D) the mass of the neutron
A) isotope B) atomic number C) charge D) mass number
A) isotope number from atomic number B) atomic number from electron number C) mass number from atomic number D) atomic number from mass number
A) like planets orbiting the sun. B) like beach balls on water waves. C) like balls rolling down a hill. D) like popcorn in a popper.
A) the most likely locations of electrons in an atom B) the number of electrons in an atom C) the mass of the electrons in the atom D) the precise location 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) 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) their masses are identical C) They are isotopes of oxygen D) They have the same mass number
A) column to column B) element to element C) group to group D) row to row
A) sodium, chromium, copper B) iodine, iron, nickel C) phosphorus, nitrogen, oxygen D) helium, carbon, gold
A) the discovery of subatomic particles. B) the immediate acceptance by other scientists. C) the discovery of elements with predicted properties. D) the discovery of the nucleus.
A) none B) four C) two D) three
A) increases then decreases B) decreases C) increases D) stays the same
A) neutron B) chlorine-35 atom C) proton D) carbon-12 atom
A) -2 B) 0 C) -1 D) +1
A) 0 B) 1/1840 C) 1/18 D) 1
A) chemical properties B) number of neutrons C) mass D) period
A) losing or gaining electrons B) changing from one period to another C) changing from lithium into fluorine D) losing or gaining protons
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 can form compounds with bright colors B) they are highly reactive 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) do not form compounds C) have large atomic masses but small atomic numbers D) are extremely hard
A) on the bottom B) in the middle C) on the right D) on the left
A) one mole of a pure substance B) one liter of a pure substance C) one gram of a pure substance D) one kilogram of a pure substance.
A) 172 B) 79 C) 35 D) 80
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