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