A) each element contributes an equal number of atoms. B) their volumes are always equal. C) their masses are always equal. D) the ratio of their masses is always the same.
A) There is a dense, positively charged mass in the center of an atom. B) Negative and positive charges are spread evenly throughout an atom. C) Alpha particles have a positive charge. D) Gold is not as dense as previously thought.
A) concentrated at multiple sites in an atom. B) concentrated in the center of an atom. C) spread evenly throughout an atom. D) located in the space outside the nucleus.
A) proton B) electron C) neutron
A) Protons, neutrons, and electrons all have about the same mass. B) Unlike protons or neutrons, electrons have no mass. C) An electron has far less mass then either a proton or a neutron. D) Neutrons have no charge and no mass.
A) the mass of the neutron B) the number of neutrons C) the number of protons D) the charge on the electrons
A) charge B) isotope C) mass number D) atomic number
A) isotope number from atomic number B) atomic number from electron number C) mass 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 planets orbiting the sun. D) like beach balls on water waves.
A) the precise location of electrons in an atom B) the most likely locations of electrons in an atom C) the mass of the electrons in the atom D) the number of electrons in an atom
A) they are usually gases B) they are located in the left-most column of the periodic table C) the are extremely nonreactive D) they form negative ions
A) electric charge of a substance B) volume of a substance C) amount of a substance D) mass of a substance
A) atomic mass unit B) mass number C) isotope number D) atomic number
A) the number of valence electrons in atoms of the element B) how tightly atoms are packed in the element C) the ratio of protons to neutrons in atoms of the element D) its atomic mass
A) They have the same mass number B) their masses are identical C) They are isotopes of oxygen D) they do not have the same number of protons
A) element to element B) column to column C) row to row D) group to group
A) sodium, chromium, copper B) phosphorus, nitrogen, oxygen C) helium, carbon, gold D) iodine, iron, nickel
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) three C) none D) two
A) stays the same B) increases then decreases C) increases D) decreases
A) carbon-12 atom B) chlorine-35 atom C) neutron D) proton
A) -1 B) 0 C) -2 D) +1
A) 1/1840 B) 1/18 C) 0 D) 1
A) number of neutrons B) chemical properties C) period D) mass
A) changing from one period to another B) losing or gaining protons C) losing or gaining electrons D) changing from lithium into fluorine
A) one-twelfth the mass of a carbon-12 atom B) one-half the mass of a hydrogen atom C) one-fifteenth the mass of a nitrogen-15 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) are extremely hard C) do not form compounds D) have large atomic masses but small atomic numbers
A) on the bottom B) on the left C) on the right D) in the middle
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) 80 B) 35 C) 172 D) 79
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