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