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