A) their volumes are always equal. B) each element contributes an equal number of atoms. C) the ratio of their masses is always the same. D) their masses are always equal.
A) There is a dense, positively charged mass in the center of an atom. B) Negative and positive charges are spread evenly throughout an atom. C) Gold is not as dense as previously thought. D) Alpha particles have a positive charge.
A) located in the space outside the nucleus. B) concentrated at multiple sites in an atom. C) concentrated in the center of an atom. D) spread evenly throughout an atom.
A) electron B) proton C) neutron
A) An electron has far less mass then either a proton or a neutron. B) Protons, neutrons, and electrons all have about the same mass. 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 charge on the electrons C) the number of protons D) the number of neutrons
A) isotope B) atomic number C) mass number D) charge
A) atomic number from mass number B) isotope number from atomic number C) atomic number from electron number D) mass number from atomic number
A) like beach balls on water waves. B) like popcorn in a popper. C) like balls rolling down a hill. D) like planets orbiting the sun.
A) the mass of the electrons in the atom B) the most likely locations of electrons in an atom C) the precise location of electrons in an atom D) the number 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) electric charge of a substance B) volume of a substance C) amount of a substance D) mass of a substance
A) atomic mass unit B) atomic number C) mass number D) isotope number
A) its atomic mass B) how tightly atoms are packed in the element C) the number of valence electrons in atoms of the element D) the ratio of protons to neutrons in atoms of the element
A) they do not have the same number of protons B) They are isotopes of oxygen C) They have the same mass number D) their masses are identical
A) column to column B) group to group C) element to element D) row to row
A) iodine, iron, nickel B) phosphorus, nitrogen, oxygen C) helium, carbon, gold D) sodium, chromium, copper
A) the immediate acceptance by other scientists. B) the discovery of subatomic particles. C) the discovery of the nucleus. D) the discovery of elements with predicted properties.
A) two B) three C) four D) none
A) decreases B) increases then decreases C) stays the same D) increases
A) proton B) carbon-12 atom C) neutron D) chlorine-35 atom
A) +1 B) -2 C) -1 D) 0
A) 1 B) 0 C) 1/1840 D) 1/18
A) chemical properties B) mass C) number of neutrons D) period
A) losing or gaining protons B) changing from lithium into fluorine C) losing or gaining electrons D) changing from one period to another
A) one-twelfth the mass of a carbon-12 atom B) one-fourth the mass of a lithium atom C) one-fifteenth the mass of a nitrogen-15 atom D) one-half the mass of a hydrogen 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) do not form compounds C) are extremely hard D) can conduct electric current only under certain conditions
A) on the left B) on the bottom C) in the middle D) on the right
A) one gram of a pure substance B) one mole of a pure substance C) one liter of a pure substance D) one kilogram of a pure substance.
A) 172 B) 79 C) 35 D) 80
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