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