A) the ratio of their masses is always the same. B) their volumes are always equal. C) each element contributes an equal number of atoms. D) their masses are always equal.
A) Alpha particles have a positive charge. 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) Gold is not as dense as previously thought.
A) spread evenly throughout an atom. B) concentrated in the center of an atom. C) concentrated at multiple sites in an atom. D) located in the space outside the nucleus.
A) proton B) neutron C) electron
A) Neutrons have no charge and no mass. B) Unlike protons or neutrons, electrons have no mass. C) An electron has far less mass then either a proton or a neutron. D) Protons, neutrons, and electrons all have about the same mass.
A) the charge on the electrons B) the number of protons C) the number of neutrons D) the mass of the neutron
A) charge B) isotope C) atomic number D) mass number
A) isotope number from atomic number B) atomic number from mass number C) mass number from atomic number D) atomic number from electron number
A) like popcorn in a popper. B) like beach balls on water waves. C) like planets orbiting the sun. 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) the are extremely nonreactive C) they are usually gases D) they form negative ions
A) amount of a substance B) electric charge 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) the number of valence electrons in atoms of the element C) how tightly atoms are packed in the element D) the ratio of protons to neutrons in atoms of the element
A) They are isotopes of oxygen B) their masses are identical C) they do not have the same number of protons D) They have the same mass number
A) element to element B) group to group C) row to row D) column to column
A) phosphorus, nitrogen, oxygen B) sodium, chromium, copper C) iodine, iron, nickel D) helium, carbon, gold
A) the discovery of subatomic particles. B) the discovery of elements with predicted properties. C) the immediate acceptance by other scientists. D) the discovery of the nucleus.
A) three B) none C) two D) four
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) +1 B) -1 C) -2 D) 0
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 electrons B) changing from one period to another C) changing from lithium into fluorine D) losing or gaining protons
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 can form compounds with bright colors B) they are rare in nature C) they are highly reactive D) They exist as single elements rather than molecules
A) do not form compounds B) are extremely hard C) have large atomic masses but small atomic numbers D) can conduct electric current only under certain conditions
A) on the left B) in the middle C) on the bottom D) on the right
A) one mole of a pure substance B) one liter of a pure substance C) one kilogram of a pure substance. D) one gram of a pure substance
A) 35 B) 172 C) 80 D) 79
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