Observing neutrinos from the Sun is an important way to check the fusion rate, but it can be very tough to build a machine that can detect these particles. What trouble did the most recent experiment, Borexino, have to overcome

The trouble that the most recent experiment, Borexino, have to overcome was that

neutrinos hardly interact with matter and so radioactive decay of ant material inside the detector could look exactly like a neutrino interaction too

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.

you get 2.3=1.21*\frac{a}2 or 4.6=1.21a or a=3.802 (b)

explanation: