A) each element contributes an equal number of atoms. B) the ratio of their masses is always the same. C) their volumes are always equal. D) their masses are always equal.
A) There is a dense, positively charged mass in the center of an atom. B) Gold is not as dense as previously thought. C) Negative and positive charges are spread evenly throughout an atom. D) Alpha particles have a positive charge.
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) electron B) neutron C) proton
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 protons B) the charge on the electrons C) the number of neutrons D) the mass of the neutron
A) charge B) atomic number C) isotope D) mass number
A) atomic number from mass number B) atomic number from electron number C) isotope number from atomic number D) mass number from atomic number
A) like planets orbiting the sun. B) like beach balls on water waves. C) like balls rolling down a hill. D) like popcorn in a popper.
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) they form negative ions B) the are extremely nonreactive C) they are usually gases D) they are located in the left-most column of the periodic table
A) electric charge of a substance B) mass of a substance C) volume of a substance D) amount of a substance
A) atomic number B) mass number C) atomic mass unit D) isotope number
A) its atomic mass B) the ratio of protons to neutrons in atoms of the element C) how tightly atoms are packed in the element D) the number of valence electrons in atoms of the element
A) They are isotopes of oxygen B) their masses are identical C) They have the same mass number D) they do not have the same number of protons
A) column to column B) row to row C) element to element D) group to group
A) iodine, iron, nickel B) helium, carbon, gold C) phosphorus, nitrogen, oxygen D) sodium, chromium, copper
A) the discovery of subatomic particles. B) the immediate acceptance by other scientists. C) the discovery of elements with predicted properties. D) the discovery of the nucleus.
A) three B) none C) two D) four
A) increases B) decreases C) stays the same D) increases then decreases
A) carbon-12 atom B) neutron C) chlorine-35 atom D) proton
A) -1 B) 0 C) -2 D) +1
A) 0 B) 1 C) 1/1840 D) 1/18
A) mass B) number of neutrons C) chemical properties D) period
A) changing from one period to another B) losing or gaining electrons C) losing or gaining protons D) changing from lithium into fluorine
A) one-fifteenth the mass of a nitrogen-15 atom B) one-half the mass of a hydrogen atom C) one-fourth the mass of a lithium atom D) one-twelfth the mass of a carbon-12 atom
A) they can form compounds with bright colors B) they are rare in nature C) They exist as single elements rather than molecules D) they are highly reactive
A) are extremely hard B) have large atomic masses but small atomic numbers C) do not form compounds D) can conduct electric current only under certain conditions
A) on the bottom B) on the left C) on the right D) in the middle
A) one gram of a pure substance B) one mole of a pure substance C) one liter of a pure substance D) one kilogram of a pure substance.
A) 172 B) 79 C) 80 D) 35
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