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