Answer:
Pb(NO3)2 + 2NaCl = 2NaNO3 + PbCl2
Sun is the primary source of energy.
It is a chain of amino acids and the subunit of a protein
I am not great at this stuff, but you need to start by writing out how many of each element there are in the product and in the reactions. It is a lot of math and trying to make the equal on both sides
have a look at the picture i’ve attached to see if it helps, let me know if you want me to go over it in more detail and i will tomorrow morning :)