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