Answer:
Atomic number: 13
Electron Configuration:[NE] 3s²3p¹
Valence electron: 3
The function of the limb is to help them get around and move. They might be similar in the way they’re structured? I don’t have a picture so I can’t tell. And you can assume that at one point these four animals all shared a common ancestor. Hope I helped!
Acetylcholine..
hope it helps
