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