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