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) There is a dense, positively charged mass in the center of an atom. C) Negative and positive charges are spread evenly throughout an atom. D) Alpha particles have a positive charge.
A) located in the space outside the nucleus. B) spread evenly throughout an atom. C) concentrated in the center of an atom. D) concentrated at multiple sites in an atom.
A) proton B) electron C) neutron
A) Unlike protons or neutrons, electrons have no mass. B) An electron has far less mass then either a proton or a neutron. C) Protons, neutrons, and electrons all have about the same mass. 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) charge B) mass number C) isotope D) atomic number
A) isotope number from atomic number B) atomic number from mass number C) mass number from atomic number D) atomic number from electron number
A) like planets orbiting the sun. B) like balls rolling down a hill. C) like beach balls on water waves. D) like popcorn in a popper.
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 form negative ions C) the are extremely nonreactive D) they are located in the left-most column of the periodic table
A) amount of a substance B) mass of a substance C) volume of a substance D) electric charge of a substance
A) mass number B) atomic mass unit C) atomic number D) isotope 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) 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) 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 elements with predicted properties. B) the discovery of the nucleus. C) the immediate acceptance by other scientists. D) the discovery of subatomic particles.
A) four B) two C) none D) three
A) stays the same B) increases C) decreases D) increases then decreases
A) proton B) neutron C) chlorine-35 atom D) carbon-12 atom
A) 0 B) +1 C) -1 D) -2
A) 1/1840 B) 1/18 C) 0 D) 1
A) period B) number of neutrons C) mass 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-half the mass of a hydrogen atom B) one-twelfth the mass of a carbon-12 atom C) one-fourth the mass of a lithium atom D) one-fifteenth the mass of a nitrogen-15 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) have large atomic masses but small atomic numbers B) are extremely hard C) do not form compounds D) can conduct electric current only under certain conditions
A) on the right B) on the left C) in the middle D) on the bottom
A) one liter of a pure substance B) one mole of a pure substance C) one gram of a pure substance D) one kilogram of a pure substance.
A) 80 B) 172 C) 35 D) 79
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