This will interfere and destabilize this CIS three hexane. In other words, there is this bumping effect when these two single bonds rotate. And this means or this creates a high energy destabilizing interaction in the CIS compound. What about our trans compound? Let's suppose we move this ethyl group into or onto the bottom and now we have our transexane. So now no matter how much they rotate, there's no interaction between these destabilizing ethyl groups between these large ethyl groups.