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