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