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