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) Gold is not as dense as previously thought. 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) Alpha particles have a positive charge.
A) concentrated at multiple sites in an atom. B) spread evenly throughout an atom. C) located in the space outside the nucleus. D) concentrated in the center of an atom.
A) electron B) neutron C) proton
A) An electron has far less mass then either a proton or a neutron. B) Protons, neutrons, and electrons all have about the same mass. C) Unlike protons or neutrons, electrons have no mass. D) Neutrons have no charge and no mass.
A) the number of neutrons B) the mass of the neutron C) the number of protons D) the charge on the electrons
A) mass number B) isotope C) atomic number D) charge
A) mass number from atomic number B) atomic number from electron number C) isotope number from atomic number D) atomic number from mass number
A) like popcorn in a popper. B) like balls rolling down a hill. C) like beach balls on water waves. D) like planets orbiting the sun.
A) the number of electrons in an atom B) the mass of the electrons in the atom C) the most likely locations of electrons in an atom D) the precise location of electrons in an atom
A) the are extremely nonreactive B) they are located in the left-most column of the periodic table C) they form negative ions D) they are usually gases
A) mass of a substance B) volume of a substance C) amount of a substance D) electric charge of a substance
A) atomic mass unit B) mass number C) atomic number 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) they do not have the same number of protons C) their masses are identical D) They are isotopes of oxygen
A) element to element B) row to row C) group to group D) column to column
A) helium, carbon, gold B) iodine, iron, nickel C) phosphorus, nitrogen, oxygen D) sodium, chromium, copper
A) the discovery of elements with predicted properties. B) the discovery of the nucleus. C) the discovery of subatomic particles. D) the immediate acceptance by other scientists.
A) three B) four C) two D) none
A) increases then decreases B) decreases C) stays the same D) increases
A) carbon-12 atom B) neutron C) proton D) chlorine-35 atom
A) 0 B) -2 C) +1 D) -1
A) 0 B) 1/1840 C) 1 D) 1/18
A) number of neutrons B) chemical properties C) mass D) period
A) changing from one period to another B) losing or gaining electrons C) losing or gaining protons D) changing from lithium into fluorine
A) one-half the mass of a hydrogen atom B) one-fourth the mass of a lithium atom C) one-twelfth the mass of a carbon-12 atom D) one-fifteenth the mass of a nitrogen-15 atom
A) they can form compounds with bright colors B) they are rare in nature C) they are highly reactive D) They exist as single elements rather than molecules
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 bottom B) in the middle C) on the left D) on the right
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) 35 B) 79 C) 80 D) 172
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