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