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