This is a gentle introduction to the new physics puzzle involving Repulsion Gel. This blue gel essentially bounces you around, but there's a few keys things to remember:
1). You bounce up at exactly the same speed and height that you land on it.
2). You can hold down the duck key as you walk over it to prevent you from bouncing.
3). If you're running over blue gel at speed and then press jump, you'll gain a boost in horizontal distance, as reflected in your running speed on the gel.
With those pointers in mind, let's start the first of eight chambers for this chapter!
As you enter the room, place a portal on the wall opposite, bounce off of the blue gel in the pit and then look up and to your left for a viewable section of wall. Your exit portal needs to go here, so step through and look over the ledge to your right.
Now take it back through the lower portal and set it on the square red button to open the exit on the ledge opposite, simply repeat the first step of jumping down and across to finish the first gel-based chamber.