Mass is always conserved in a physical change. Energy may be released or absorbed when a substance changes from one physical state to another. In a chemical change, a chemical reaction yields a completely new substance. A substance's particles are changed during a chemical reaction.
Answer:
Atom
Explanation:
my theory:
Atoms are their own substance. It's atom because if you tried to break an atom, you would be going into nuclear physics. That would be unsafe and dangerous.
Answer:
A. No precipitate is formed
Explanation:
Hello,
In this case, since the reactions are:
We evidence no formation of insoluble salts or precipitates since both calcium and barium chlorides are largely soluble in water due to the ionic bond which binds them, thus A. No precipitate is formed.
Regards.
Answer:
how can I solve this ?4Al+3O2 produce 2Al2O3 find a) oxygen atoms needed to react with 5.4 g of aluminium b) grams of oxygen needed to react with 0.6 mol of aluminium?
(A) n=m/M,
n(Al)=5.4/27=0.2 moles
n(O2)=n(Al)*3/4=0.2*3/4=0.15 moles
Number of oxygen atoms= n(O2)*Avogadro's number
=0.15*6.02*10^23=9.03*10^22 oxgyen atoms
(B)
n=m/M
n(Al)=0.6/27=0.02222 moles
n(O2)=n(Al)*3/4=0.016666 moles
m=n*M
m(O2)=0.0166666*32=0.53333 grams
