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