A) each element contributes an equal number of atoms. B) their volumes are always equal. C) the ratio of their masses is always the same. D) their masses are always equal.
A) Negative and positive charges are spread evenly throughout an atom. B) Gold is not as dense as previously thought. C) There is a dense, positively charged mass in the center of an atom. D) Alpha particles have a positive charge.
A) spread evenly throughout an atom. B) located in the space outside the nucleus. C) concentrated at multiple sites in an atom. D) concentrated in the center of an atom.
A) electron B) proton C) neutron
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 charge on the electrons C) the number of neutrons D) the number of protons
A) charge B) atomic number C) isotope D) mass number
A) mass number from atomic number B) isotope number from atomic number C) atomic number from mass number D) atomic number from electron number
A) like popcorn in a popper. B) like beach balls on water waves. C) like balls rolling down a hill. D) like planets orbiting the sun.
A) the mass of the electrons in the atom B) the number of electrons in an atom C) the most likely locations of electrons in an atom D) the precise location of electrons in an atom
A) they are located in the left-most column of the periodic table B) they are usually gases C) the are extremely nonreactive D) they form negative ions
A) mass of a substance B) electric charge of a substance C) amount of a substance D) volume of a substance
A) mass number B) atomic number C) isotope number D) atomic mass unit
A) its atomic mass B) how tightly atoms are packed in the element C) the ratio of protons to neutrons in atoms of the element 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) column to column B) element to element C) row to row D) group to group
A) phosphorus, nitrogen, oxygen B) iodine, iron, nickel C) sodium, chromium, copper D) helium, carbon, gold
A) the discovery of the nucleus. B) the immediate acceptance by other scientists. C) the discovery of elements with predicted properties. D) the discovery of subatomic particles.
A) four B) none C) two D) three
A) increases then decreases B) increases C) decreases D) stays the same
A) proton B) neutron C) chlorine-35 atom D) carbon-12 atom
A) -1 B) -2 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 electrons B) changing from lithium into fluorine C) losing or gaining protons 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) 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) on the left B) on the right C) in the middle D) on the bottom
A) one mole of a pure substance B) one gram of a pure substance C) one kilogram of a pure substance. D) one liter of a pure substance
A) 35 B) 80 C) 79 D) 172
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