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