A) their masses are always equal. B) their volumes are always equal. C) the ratio of their masses is always the same. D) each element contributes an equal number of atoms.
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) Gold is not as dense as previously thought. D) Alpha particles have a positive charge.
A) spread evenly throughout an atom. B) located in the space outside the nucleus. C) concentrated at multiple sites in an atom. D) concentrated in the center of 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 charge on the electrons B) the mass of the neutron C) the number of neutrons D) the number of protons
A) mass number B) atomic number C) isotope D) charge
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 popcorn in a popper. B) like planets orbiting the sun. C) like beach balls on water waves. D) like balls rolling down a hill.
A) the number of electrons in an atom B) the mass of the electrons in the atom C) the precise location of electrons in an atom D) the most likely locations of electrons in an atom
A) the are extremely nonreactive B) they form negative ions C) they are located in the left-most column of the periodic table D) they are usually gases
A) electric charge of a substance B) mass of a substance C) volume of a substance D) amount of a substance
A) mass number B) atomic number C) isotope number D) atomic mass unit
A) how tightly atoms are packed in the element B) the number of valence electrons in atoms of the element C) the ratio of protons to neutrons in atoms of the element D) its atomic mass
A) they do not have the same number of protons B) their masses are identical C) They have the same mass number D) They are isotopes of oxygen
A) column to column B) row to row C) element to element D) group to group
A) phosphorus, nitrogen, oxygen B) sodium, chromium, copper C) iodine, iron, nickel D) helium, carbon, gold
A) the discovery of the nucleus. B) the immediate acceptance by other scientists. C) the discovery of subatomic particles. D) the discovery of elements with predicted properties.
A) two B) none C) three D) four
A) increases then decreases B) stays the same C) increases D) decreases
A) neutron B) carbon-12 atom C) proton D) chlorine-35 atom
A) 0 B) -1 C) +1 D) -2
A) 1/1840 B) 1 C) 0 D) 1/18
A) chemical properties B) number of neutrons C) period D) mass
A) changing from lithium into fluorine B) changing from one period to another C) losing or gaining electrons D) losing or gaining protons
A) one-fourth the mass of a lithium atom B) one-half the mass of a hydrogen atom C) one-twelfth the mass of a carbon-12 atom D) one-fifteenth the mass of a nitrogen-15 atom
A) they are highly reactive B) they can form compounds with bright colors C) they are rare in nature D) They exist as single elements rather than molecules
A) do not form compounds B) have large atomic masses but small atomic numbers C) can conduct electric current only under certain conditions D) are extremely hard
A) on the bottom B) on the left C) on the right D) in the middle
A) one kilogram of a pure substance. B) one gram of a pure substance C) one mole of a pure substance D) one liter of a pure substance
A) 79 B) 172 C) 80 D) 35
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