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