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) There is a dense, positively charged mass in the center of an atom. D) Alpha particles have a positive charge.
A) concentrated in the center of an atom. B) located in the space outside the nucleus. C) concentrated at multiple sites in an atom. D) spread evenly throughout an atom.
A) electron B) neutron C) proton
A) Neutrons have no charge and no mass. B) Unlike protons or neutrons, electrons have no mass. C) Protons, neutrons, and electrons all have about the same mass. D) An electron has far less mass then either a proton or a neutron.
A) the number of neutrons B) the mass of the neutron C) the number of protons D) the charge on the electrons
A) mass number B) charge C) atomic number D) isotope
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 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 number of electrons in an atom D) the precise location of electrons in an atom
A) they are usually gases B) they form negative ions C) they are located in the left-most column of the periodic table D) the are extremely nonreactive
A) mass of a substance B) volume of a substance C) electric charge of a substance D) amount of a substance
A) mass number B) atomic mass unit C) isotope number D) atomic number
A) the ratio of protons to neutrons in atoms of the element B) the number of valence electrons in atoms of the element C) its atomic mass D) how tightly atoms are packed in the element
A) They are isotopes of oxygen B) they do not have the same number of protons C) They have the same mass number D) their masses are identical
A) column to column B) element to element C) group to group D) row to row
A) phosphorus, nitrogen, oxygen B) sodium, chromium, copper C) helium, carbon, gold D) iodine, iron, nickel
A) the discovery of the nucleus. B) the discovery of subatomic particles. C) the discovery of elements with predicted properties. D) the immediate acceptance by other scientists.
A) four B) none C) three D) two
A) decreases B) increases then decreases C) stays the same D) increases
A) carbon-12 atom B) chlorine-35 atom C) neutron D) proton
A) -1 B) +1 C) 0 D) -2
A) 1/1840 B) 0 C) 1 D) 1/18
A) period B) number of neutrons C) chemical properties D) mass
A) changing from one period to another B) changing from lithium into fluorine C) losing or gaining protons D) losing or gaining electrons
A) one-fourth the mass of a lithium atom B) one-fifteenth the mass of a nitrogen-15 atom C) one-twelfth the mass of a carbon-12 atom D) one-half the mass of a hydrogen atom
A) they are rare in nature B) They exist as single elements rather than molecules C) they can form compounds with bright colors D) they are highly reactive
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) in the middle B) on the bottom C) on the left D) on the right
A) one gram of a pure substance B) one mole of a pure substance C) one kilogram of a pure substance. D) one liter of a pure substance
A) 172 B) 79 C) 35 D) 80
|