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