A) their masses are always equal. B) the ratio of their masses is always the same. C) their volumes are always equal. D) each element contributes an equal number of atoms.
A) Gold is not as dense as previously thought. B) There is a dense, positively charged mass in the center of an atom. C) Negative and positive charges are spread evenly throughout an atom. D) Alpha particles have a positive charge.
A) concentrated at multiple sites in an atom. B) located in the space outside the nucleus. C) spread evenly throughout an atom. D) concentrated in the center of an atom.
A) proton B) electron C) neutron
A) Neutrons have no charge and no mass. B) Unlike protons or neutrons, electrons have 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 number of protons B) the number of neutrons C) the mass of the neutron D) the charge on the electrons
A) charge B) isotope C) mass number D) atomic number
A) isotope number from atomic number B) atomic number from mass number C) mass number from atomic number D) atomic number from electron 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 mass of the electrons in the atom B) the number of electrons in an atom C) the precise location of electrons in an atom D) the most likely locations 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) mass of a substance C) electric charge of a substance D) amount of a substance
A) atomic number B) atomic mass unit C) isotope number D) mass number
A) its atomic mass B) how tightly atoms are packed in the element C) the ratio of protons to neutrons in atoms of 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) element to element B) column to column C) group to group D) row to row
A) sodium, chromium, copper B) iodine, iron, nickel C) helium, carbon, gold D) phosphorus, nitrogen, oxygen
A) the immediate acceptance by other scientists. B) the discovery of subatomic particles. C) the discovery of the nucleus. D) the discovery of elements with predicted properties.
A) two B) none C) four D) three
A) increases B) decreases C) stays the same D) increases then decreases
A) chlorine-35 atom B) neutron C) proton D) carbon-12 atom
A) 0 B) -2 C) -1 D) +1
A) 1 B) 1/1840 C) 0 D) 1/18
A) period B) chemical properties C) number of neutrons D) mass
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-fifteenth the mass of a nitrogen-15 atom B) one-twelfth the mass of a carbon-12 atom C) one-half the mass of a hydrogen 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 exist as single elements rather than molecules D) they are rare in nature
A) have large atomic masses but small atomic numbers B) do not form compounds C) can conduct electric current only under certain conditions D) are extremely hard
A) in the middle B) on the bottom C) on the left D) on the right
A) one mole of a pure substance B) one kilogram of a pure substance. C) one gram of a pure substance D) one liter of a pure substance
A) 80 B) 172 C) 79 D) 35
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