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