How can a methyl cation exist without 8 valence electrons So far I have been taught that everything wants to achieve noble gas configuration - 8 electrons in the outer shell.

I came across a methyl cation. Which contains a positive carbon, no lone pairs and 3 bonding pairs of electrons so 6 electrons in total. 6 electrons are obviously less than 8 electrons so how can it exist as it defies apparently the rules I have been taught.

Thanks,

Daniel
The way you put it that everything wants to achieve noble gas configuration is a good rule of thumb for predicting molecules that are stable and long-lived. However, not everything is in equilibrium. A methyl cation certainly exists, and it certainly wants to achieve the noble gas configuration, but it still takes time to do so. So we can conclude that the methyl cation is an unstable, short-lived, highly reactive molecule, which is true. And you are totally right to explain this with the tendency of having a closed electronic shell.