Explanation:
The mass per unit volume of a substance is called density .
Answer:
C
Explanation:
C) an atom with an atomic number of 18
Answer:
the answer is electron shell
I hope it helps you
Answer: 8.25 moles of oxygen are produced.
Explanation: The reaction follows:

By Stoichiometry,
As, 4 moles of Aluminium is produced by 2 moles of aluminium oxide
11 moles of aluminium will be produced by = 
Now, 2 moles of aluminium oxide produces 3 moles of oxygen, so
5.5 moles of Aluminium oxide will produce = 
Hence, 8.25 moles of oxygen will be produced.
D excretory system releases waste like when you use the bathroom and stuff. :)