T1-T2
40°+273=313-20°+273=293
313-293=20
the final temp is 20°
I have completed the problem
Option 2, Br. I'll go over why all other three options are incorrect.
Option 1 - Krypton is a Noble gas, and so it doesn't need to accept electrons since it has an octet.
Option 3 and 4 - Both Calcium and Barium are alkaline earth metals, and give away electrons, since they only have 2.
-T.B.
B.) Copper
The alkaline battery gets its call because of the fact it has an alkaline electrolyte of potassium hydroxide, as adverse to the acidic electrolyte of the zinc-carbon batteries that are presented interior the same nominal voltages and actual length.