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