Which of the following is the correct definition of minerals? a a naturally occurring, inorganic solid that has a crystal shape and a definite chemical composition b a naturally occurring, inorganic solid that forms through crystallization of melted materials c a naturally occurring, organic solid that forms through crystallization of materials dissolving in water d a naturally occurring, organic solid that has a crystal shape and a definite chemical composition

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

Compare and contrast physical changes with chemical changes.

Name the element in group 17, period 2. (periodic table)