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