A) their volumes are always equal. B) their masses are always equal. C) each element contributes an equal number of atoms. D) the ratio of their masses is always the same.
A) Gold is not as dense as previously thought. B) Alpha particles have a positive charge. C) There is a dense, positively charged mass in the center of an atom. D) Negative and positive charges are spread evenly throughout an atom.
A) concentrated in the center of an atom. B) located in the space outside the nucleus. C) concentrated at multiple sites in an atom. D) spread evenly throughout an atom.
A) electron B) neutron C) proton
A) An electron has far less mass then either a proton or a neutron. B) Unlike protons or neutrons, electrons have no mass. C) Protons, neutrons, and electrons all have about the same mass. D) Neutrons have no charge and no mass.
A) the number of protons B) the mass of the neutron C) the charge on the electrons D) the number of neutrons
A) atomic number B) isotope C) charge D) mass number
A) mass number from atomic number B) atomic number from mass number C) isotope number from atomic 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 most likely locations of electrons in an atom B) the precise location of electrons in an atom C) the number of electrons in an atom D) the mass of the electrons in the atom
A) they are located in the left-most column of the periodic table B) the are extremely nonreactive C) they form negative ions D) they are usually gases
A) volume of a substance B) electric charge of a substance C) mass of a substance D) amount of a substance
A) isotope number B) mass number C) atomic mass unit D) atomic number
A) the number of valence electrons in atoms of the element B) the ratio of protons to neutrons in atoms of the element C) how tightly atoms are packed in the element D) its atomic mass
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) column to column B) group to group C) row to row D) element to element
A) iodine, iron, nickel B) helium, carbon, gold C) phosphorus, nitrogen, oxygen D) sodium, chromium, copper
A) the discovery of the nucleus. B) the discovery of elements with predicted properties. C) the immediate acceptance by other scientists. D) the discovery of subatomic particles.
A) three B) none C) two D) four
A) stays the same B) decreases C) increases then decreases D) increases
A) neutron B) chlorine-35 atom C) proton D) carbon-12 atom
A) -1 B) +1 C) 0 D) -2
A) 1/18 B) 1/1840 C) 1 D) 0
A) chemical properties B) number of neutrons C) mass D) period
A) changing from lithium into fluorine B) changing from one period to another C) losing or gaining protons D) losing or gaining electrons
A) one-fifteenth the mass of a nitrogen-15 atom B) one-half the mass of a hydrogen atom C) one-twelfth the mass of a carbon-12 atom D) one-fourth the mass of a lithium atom
A) they are highly reactive B) They exist as single elements rather than molecules C) they are rare in nature 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 left B) in the middle C) on the bottom D) on the right
A) one gram of a pure substance B) one mole of a pure substance C) one liter of a pure substance D) one kilogram of a pure substance.
A) 172 B) 80 C) 35 D) 79
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