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