Answer:
the answer is electrons
Explanation:
the answer of electrochemistry unit test
1)electrons
2)calcium
3)oxidation
4) Na
5)+1
6)N = -3, H = +1, Cl = -1
7) Cr
8) Mercury
9) Zn(s)
10)Two half-reaction must be physically separated.
11) anode only
12) the moving electrons
13) graphite
14) a direct current
15) O diffuses through cathode
16) electrolysis
17)all the above
18) hydrogen gas and oxygen gas
19) decomposition of metal layer on a material
