Which is true of an atom? A. The valence electrons make up the majority of the mass and volume of an atom. B. The electron cloud makes up the majority of the mass and volume of an atom. C. The valence electrons make up the majority of the mass of an atom but do not take up much volume. D. The electron cloud makes up the majority of the volume of an atom but does not have much mass.

Asample of aluminum foil contains 8.60 × 1023 atoms. what is the mass of the foil?

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this