Physical changes happen when you do/mix something that can be reversed. Best example is ripping a paper, you can just tape it back together so it is just an observable thing that changes, which is a physical change. Chemical changes happen when you mix things and they make a new substance and can’t be reversed. The best example of this is the Statue of Liberty, which changed in color due to the chemical change between the oxygen and copper, which created a new substance (rust) which made it green instead of copper.
Sorry for the long answer but hope this helps!
Answer:
Your stomach lining also secretes hydrochloric acid, which creates the ideal conditions for the protein-digesting enzymes to work. The potent hydrochloric acid kills bacteria, protecting your body from harmful microbes which can enter your body in food.
The balanced reaction is 3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
).
<u>Explanation</u>:
A chemical equation is said to be balanced when the total number of atoms present on the reactants side is equal to the total number of atoms present on the product side.
The unbalanced chemical equation is as follows,
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
To balance this equation, you need to look at how many atoms of each element are present on each side of the chemical equation.
Calcium has 1 atom on the reactant and 3 on the products side. To balance the reaction we need to multiply the calcium atom by 3 on the reactants side.
3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
Now Nitrogen has a coefficient of 2 on both sides of the reaction. Hence the balanced chemical equation will thus be
3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
A colored line, as long as it is one single piece, not broken