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