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