En el aire, el oxígeno representa el 21%en volumen. Una disolución concentrada comercial de ácido clorhídrico, HCl, tiene una concentración de l35% en masa.
Una disolución diluida de hidróxido de sodio, presente en un laboratorio, puede tener una concentración de 2M (molar).

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

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Table sugar completely dissolved in water is an example of a?