Answer:
Elements.
Explanation:
Modern Chemistry says these are elements.
Answer:
11.0L of carbon dioxide is produced
Explanation:
Balanced equation: 
According to balanced equation, 1 mol of
produces 1 mol of 
So, 0.489 mol of
produces 0.489 mol of 
Let's assume
behaves ideally.
So, 
where P is pressure, V is volume , n is number of moles, R is gas constant and T is temperature in kelvin
Plug-in all the values in the above equation-

or, 
So, 11.0L of carbon dioxide is produced
D. For plato users
(I've had the exact same one)
Answer:
Draw circles to represent the electron shell of each atom overlapping the circles where the atoms are bonded. Add dots to represent the outer electrons of one type of atom (H). Add crosses to represent the outer electrons of the other type of atom (Cl). Make sure the electrons are always in pairs.