A) their masses are always equal. B) their volumes 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) There is a dense, positively charged mass in the center of an atom. C) Alpha particles have a positive charge. D) Negative and positive charges are spread evenly throughout an atom.
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) neutron B) proton C) electron
A) Unlike protons or neutrons, electrons have no mass. B) Protons, neutrons, and electrons all have about the same 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 number of neutrons B) the number of protons C) the mass of the neutron D) the charge on the electrons
A) isotope B) mass number C) atomic number D) charge
A) mass number from atomic number B) atomic number from electron number C) atomic number from mass number D) isotope number from atomic number
A) like popcorn in a popper. B) like beach balls on water waves. C) like planets orbiting the sun. D) like balls rolling down a hill.
A) the mass of the electrons in the atom B) the number of electrons in an atom C) the precise location of electrons in an atom D) the most likely locations 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) electric charge of a substance B) amount of a substance C) mass of a substance D) volume of a substance
A) atomic number B) mass number C) atomic mass unit D) isotope number
A) how tightly atoms are packed in the element B) its atomic mass C) the ratio of protons to neutrons in atoms of the element D) the number of valence electrons in atoms of the element
A) their masses are identical B) They have the same mass number C) They are isotopes of oxygen D) they do not have the same number of protons
A) group to group B) column to column C) element to element D) row to row
A) phosphorus, nitrogen, oxygen B) sodium, chromium, copper C) iodine, iron, nickel 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) three B) none C) four D) two
A) increases then decreases B) increases C) decreases D) stays the same
A) proton B) chlorine-35 atom C) carbon-12 atom D) neutron
A) 0 B) -2 C) -1 D) +1
A) 0 B) 1/1840 C) 1 D) 1/18
A) number of neutrons B) mass C) period D) chemical properties
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-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 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) are extremely hard B) can conduct electric current only under certain conditions C) do not form compounds D) have large atomic masses but small atomic numbers
A) on the left B) on the right C) on the bottom D) in the middle
A) one gram of a pure substance B) one liter of a pure substance C) one mole of a pure substance D) one kilogram of a pure substance.
A) 172 B) 80 C) 35 D) 79
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