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