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