A) their volumes are always equal. B) the ratio of their masses is always the same. C) their masses are always equal. D) each element contributes an equal number of atoms.
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 at multiple sites in an atom. B) spread evenly throughout an atom. C) concentrated in the center of an atom. D) located in the space outside the nucleus.
A) proton B) neutron 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 mass of the neutron C) the charge on the electrons D) the number of neutrons
A) isotope B) mass number C) atomic number D) charge
A) atomic number from electron number B) mass number from atomic number C) atomic number from mass number D) isotope number from atomic number
A) like beach balls on water waves. B) like planets orbiting the sun. C) like popcorn in a popper. D) like balls rolling down a hill.
A) the precise location of electrons in an atom B) the number of electrons in an atom C) the mass of the electrons in the atom D) the most likely locations 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) amount of a substance B) volume of a substance C) electric charge of a substance D) mass of a substance
A) mass number B) atomic number C) isotope number D) atomic mass unit
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 do not have the same number of protons B) They have the same mass number C) They are isotopes of oxygen D) their masses are identical
A) column to column B) group to group C) row to row D) element to element
A) helium, carbon, gold B) phosphorus, nitrogen, oxygen C) iodine, iron, nickel D) sodium, chromium, copper
A) the discovery of elements with predicted properties. B) the discovery of subatomic particles. C) the immediate acceptance by other scientists. D) the discovery of the nucleus.
A) none B) four C) three D) two
A) stays the same B) decreases C) increases then decreases D) increases
A) proton B) chlorine-35 atom C) neutron D) carbon-12 atom
A) +1 B) -1 C) 0 D) -2
A) 0 B) 1 C) 1/18 D) 1/1840
A) number of neutrons B) chemical properties C) mass D) period
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-twelfth the mass of a carbon-12 atom B) one-fourth the mass of a lithium atom C) one-half the mass of a hydrogen atom D) one-fifteenth the mass of a nitrogen-15 atom
A) they are highly reactive B) they are rare in nature C) They exist as single elements rather than molecules D) they can form compounds with bright colors
A) have large atomic masses but small atomic numbers B) can conduct electric current only under certain conditions C) are extremely hard D) do not form compounds
A) on the bottom B) on the left C) on the right D) in the middle
A) one liter of a pure substance B) one mole of a pure substance C) one gram of a pure substance D) one kilogram of a pure substance.
A) 172 B) 79 C) 80 D) 35
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