An interesting question. Do scientist have the capability to explain everything? No, obviously not. That lack of capability does not however mean that there is not a a scientific explanation for everything, just that our grasp of scientific knowledge is extremely small.
When it comes to the physical world and interactions therein then yes, I believe everything has scientific explanation. Whether we have yet reached the intellectual awareness, development, and comprehension to discover and understand these explanations is an ongoing process. But there is also the ever present wonder and question of whether there is something else beyond the mere physical world wherein lies the metaphysical and its inherent questions of existence, religion, spirituality, et al. I would like to think that there is something more than mere science but how does one prove or disprove something that is likely beyond human comprehension or scientific empirical study?