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