If this question needed to be asked, then there is an apparent 'something else' something more dynamic within the 'opinion' as stated in your question. Logical science would have us believe what it sees, and would have it no other way. But the fact you have asked a question, indirectly implies there is something 'else' than opinion, and indeed within 'opinion', as well as atoms and empty spaces.
Physically, what we can see, and when i say 'see' i mean, how human experience, science and human perception can show us, it is simply what we make up of arbituary units, known as atoms. So you are correct, in this sense.
However you have to consider, what you define as 'existence' you possibly mean, what is actually there... tangibly, scientifically. Then yes, only atoms and empty spaces and a lot of labelling and subjective opinions.
How far do you trust science, senses, logic and judgement? Can an opinion, tell us more? Atoms and empty spaces will never tell us that. This question truly approaches the dynamism between mathematical logic (science) and subjective human experience.