Close Properties Panel Shortcut Visual Studio

There is a shortcut for opening the properties panel in visual studio. But there is not a paired shortcut to CLOSE IT! This is really annoying. I have shortcuts to open all of the panels I use in visual studio. But I can't use any shortcuts to close them. I get that, with a mouse, the opening is much slower than the closing... But it would be nice if we could at the very least, close the ACTIVE PANEL with a shortcut. NOT close the active document. I see the shortcuts for that. I can close all documents. I just can't close the explorer, toolbox, and properties panels with a shortcut. Really annoyed.