I'm beginning my studies of chemistry at high school (I'm not a native English speaker, though) and I have some basic questions:
1) Consider the compound xenon tetroxide. In this molecule, does the xenon have its valence layer expanded? In another words, the oxygen atoms only have double covalent bonds with the Xenon?
I've tried to look for this answer but I'm still in doubt whether xenon does four dative covalent bonds (with each oxygen) or four double covalent bonds. In the first case, does not occur the expanded octet rule for xenon, right?
2) Another question; is it possible for a dative covalent bond to occur with just one electron? I mean, the atom which has more electrons in its valence layer "donates" just one electron instead of two? If the answer is "yes", can you provide me an example, please?
I'm sorry for the English mistakes. I started to learn this "chemistry vocabulary" just now.