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