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