3. Distinguish between a complex substance and an elemental substance.
A1, A2a
4. (a) What are the two general classes of ele
ments? (b) Do all elements fit definitely int
one of these classes? A1, A2e
5. Distinguish between a compound and
mixture. A1, A2, A5a
6. What are the five most abundant element
by mass in the earth's surface environment
A3d
7.) (a) What are the properties of metals? (b)
nonmetals? A2e​

What is driving behind plate tectonics (plate movment)? a) gravity only b) inertia c) convection and gravity d) the sun theres no option for science so i picked chemistry. plz

Seltzer water is created by placing water under pressure with carbon dioxide gas. which of the following statements best describe seltzer water: a. the solution will be slightly acidic b. the solution will be slightly basic. the solution will be strongly acidic. d. the solution will be strongly basic. e. the solution will be neutral

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