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