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