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