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