Answer:
An emerald can be described as a pure substance because it is a compound. it's a pure substance because it is an element. It's an impure substance because it is chemically combined, an impure substance because it is a mixture.
Explanation:
Answer: A Bronsted-Lowry acid is defined as a substance that acts as a proton donor.
Explanation:
A substance that is able to donate a proton or hydrogen ion to another substance is a Bronsted-Lowry acid.
For example, HCl is a Bronsted-Lowry acid as it dissociates to give a hydrogen ion.

Thus, we can conclude that a Bronsted-Lowry acid is defined as a substance that acts as a proton donor.
Answer:
I think B..
Explanation:
It is the sharing of electrons from one atom to another .
Answer:
Pb(NO3)2+2NaCl \to PbCl2+NaNO3
Explanation:
Lead(II) nitrate is 
Sodium Chloride is 
This is a double displacement reaction. Hence anions or cations of both the compounds are displaced to form the products.


Therefore the balanced equation is

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