A) each element contributes an equal number of atoms. B) the ratio of their masses is always the same. C) their masses are always equal. D) their volumes are always equal.
A) There is a dense, positively charged mass in the center of an atom. B) Gold is not as dense as previously thought. C) Alpha particles have a positive charge. D) Negative and positive charges are spread evenly throughout an atom.
A) located in the space outside the nucleus. B) concentrated at multiple sites in an atom. C) concentrated in the center of an atom. D) spread evenly throughout an atom.
A) neutron B) electron C) proton
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) Unlike protons or neutrons, electrons have no mass. D) Neutrons have no charge and no mass.
A) the mass of the neutron B) the number of protons C) the number of neutrons D) the charge on the electrons
A) charge B) atomic number C) isotope D) mass number
A) mass number from atomic number B) isotope number from atomic number C) atomic number from electron number D) atomic number from mass number
A) like beach balls on water waves. B) like balls rolling down a hill. C) like popcorn in a popper. D) like planets orbiting the sun.
A) the mass of the electrons in the atom B) the precise location of electrons in an atom C) the most likely locations of electrons in an atom D) the number of electrons in an atom
A) they are usually gases B) the are extremely nonreactive C) they are located in the left-most column of the periodic table D) they form negative ions
A) volume of a substance B) amount of a substance C) mass of a substance D) electric charge of a substance
A) atomic number B) isotope number C) mass number D) atomic mass unit
A) its atomic mass B) the ratio of protons to neutrons in atoms of the element C) the number of valence electrons in atoms of the element D) how tightly atoms are packed in the element
A) their masses are identical B) They have the same mass number C) they do not have the same number of protons D) They are isotopes of oxygen
A) element to element B) column to column C) row to row D) group to group
A) sodium, chromium, copper B) iodine, iron, nickel 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) none B) three C) two D) four
A) stays the same B) decreases C) increases D) increases then decreases
A) carbon-12 atom B) neutron C) chlorine-35 atom D) proton
A) +1 B) 0 C) -1 D) -2
A) 1/18 B) 0 C) 1/1840 D) 1
A) number of neutrons B) period C) mass D) chemical properties
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-fifteenth the mass of a nitrogen-15 atom B) one-half the mass of a hydrogen atom C) one-twelfth the mass of a carbon-12 atom D) one-fourth the mass of a lithium atom
A) they are rare in nature B) they can form compounds with bright colors C) They exist as single elements rather than molecules D) they are highly reactive
A) do not form compounds B) can conduct electric current only under certain conditions C) are extremely hard D) have large atomic masses but small atomic numbers
A) in the middle B) on the left C) on the right D) on the bottom
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) 79 B) 172 C) 80 D) 35
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