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