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