Is every thing related to science

Yes because...

Everything in the universe happens for a reason, and science is man's way of explaining why these things happen. Science is based on fact, rather than religion, which is based on belief, and many scientific theories can actually be proved. If they cannot be proved, then evidence for them can be suggested. For example, there are many sources of evidence for the 'big bang' (the beginning of the universe) - such as the abundance of Hydrogen and the Cosmic Microwave Background Radiation (just to name a few), yet we cannot actually prove that this was the beginning of the universe, as obviously, we cannot rewind time. This means that science can only take educated guesses, supplying proof, in regards to some things.

While science cannot PROVE everything, it CAN make educated theories, based on similar scientific studies, as to why things occur. This is why a large majority of science is purely theoretical - because our equipment is not yet advanced enough to allow us to prove everything. However, technology (and therefore science) is rapidly improving and expanding each year; it is only a matter of time.

No because...

If you argue that science can only 'explain' something by proving it (for example, we know that the most abundant element in the Earth's atmosphere is Nitrogen, and science can prove this), then science can never know EVERYTHING, as there are many things that cannot be proved.

Following the example on the left, one example of something that cannot be proved is the creation of the universe. No one will never know how this occured, as obviously, nobody was around at the time, and so science can only ever make 'educated guesses'.