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