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) 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) concentrated at multiple sites in an atom. B) concentrated in the center of an atom. C) located in the space outside the nucleus. D) spread evenly throughout an atom.
A) neutron B) electron C) proton
A) An electron has far less mass then either a proton or a neutron. B) Neutrons have no charge and no mass. C) Unlike protons or neutrons, electrons have 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 charge on the electrons D) the number of neutrons
A) atomic number B) isotope C) charge D) mass number
A) isotope number from atomic number B) atomic number from electron number C) atomic number from mass number D) mass number from atomic number
A) like balls rolling down a hill. B) like planets orbiting the sun. C) like popcorn in a popper. D) like beach balls on water waves.
A) the most likely locations of electrons in an atom B) the precise location of electrons in an atom C) the mass of the electrons in the atom D) the number 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) electric charge of a substance B) mass of a substance C) amount of a substance D) volume of a substance
A) atomic number B) isotope number C) atomic mass unit D) mass number
A) the ratio of protons to neutrons in atoms of the element B) the number of valence electrons in atoms of the element C) its atomic mass D) how tightly atoms are packed in the element
A) their masses are identical B) They are isotopes of oxygen C) they do not have the same number of protons D) They have the same mass number
A) row to row B) group to group C) element to element D) column to column
A) sodium, chromium, copper B) helium, carbon, gold C) phosphorus, nitrogen, oxygen D) iodine, iron, nickel
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) four B) none C) three D) two
A) decreases B) stays the same C) increases D) increases then decreases
A) chlorine-35 atom B) proton C) neutron D) carbon-12 atom
A) -1 B) -2 C) +1 D) 0
A) 1 B) 1/1840 C) 0 D) 1/18
A) period B) number of neutrons C) mass D) chemical properties
A) losing or gaining electrons B) changing from one period to another C) losing or gaining protons D) changing from lithium into fluorine
A) one-fifteenth the mass of a nitrogen-15 atom B) one-half the mass of a hydrogen atom C) one-fourth the mass of a lithium atom D) one-twelfth the mass of a carbon-12 atom
A) they can form compounds with bright colors B) They exist as single elements rather than molecules C) they are rare in nature 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 right B) on the bottom C) on the left D) in the middle
A) one mole of a pure substance B) one kilogram of a pure substance. C) one gram of a pure substance D) one liter of a pure substance
A) 79 B) 80 C) 172 D) 35
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