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