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) 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) concentrated at multiple sites in an atom. D) spread evenly throughout an atom.
A) electron B) proton C) neutron
A) Protons, neutrons, and electrons all have about the same mass. B) An electron has far less mass then either a proton or a neutron. C) Neutrons have no charge and no mass. D) Unlike protons or neutrons, electrons have no mass.
A) the number of protons B) the charge on the electrons C) the mass of the neutron D) the number of neutrons
A) mass number B) charge C) isotope D) atomic number
A) atomic number from electron number B) atomic number from mass number C) isotope number from atomic number D) mass number from atomic number
A) like beach balls on water waves. B) like planets orbiting the sun. C) like balls rolling down a hill. D) like popcorn in a popper.
A) the most likely locations of electrons in an atom B) the number 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 usually gases C) the are extremely nonreactive D) they are located in the left-most column of the periodic table
A) amount of a substance B) mass of a substance C) volume of a substance D) electric charge of a substance
A) atomic mass unit B) isotope number C) atomic number D) mass number
A) the ratio of protons to neutrons in atoms of the element B) the number of valence electrons in atoms of the element C) its atomic mass D) how tightly atoms are packed in 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) row to row B) element to element C) group to group D) column to column
A) sodium, chromium, copper B) helium, carbon, gold C) phosphorus, nitrogen, oxygen D) iodine, iron, nickel
A) the immediate acceptance by other scientists. B) the discovery of the nucleus. C) the discovery of elements with predicted properties. D) the discovery of subatomic particles.
A) none B) four C) three D) two
A) increases then decreases B) increases C) stays the same D) decreases
A) neutron B) proton C) chlorine-35 atom D) carbon-12 atom
A) -2 B) -1 C) +1 D) 0
A) 1 B) 1/18 C) 0 D) 1/1840
A) mass B) number of neutrons C) period D) chemical properties
A) losing or gaining protons B) changing from lithium into fluorine 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 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) on the right B) in the middle C) on the left D) on the bottom
A) one liter of a pure substance B) one gram of a pure substance C) one kilogram of a pure substance. D) one mole of a pure substance
A) 35 B) 172 C) 80 D) 79
|