Why are there chemical reactions

What I would like to know is how things like elements interact with each other when at the very core everything is made up of mindless atoms. I assume atoms don't have some sort of programming like our DNA, so why does something happen when they interact with each other? It's like sand. Sand on top of sand does nothing. So why do we get chemical reactions when "sand" is placed on "sand"? Atoms are blank slates, building blocks, right? Just little bits that can be stacked on each other to form bigger things. But my question is why does something happen (like a chemical reaction) when one group of bits comes together with a different group of bits when atoms are just mindless little building blocks?

I apologize if this is a confusingly worded question, but I have a visual mind so it's a little difficult for me to explain in words some concepts I have.

Your conception of atoms is a little off...you shouldn't think of them as sand; that would be implying that the atoms of different elements are the same when they're not. Atoms of different elements have different numbers of electrons. These electrons orbit the atom in different orbitals. To each orbital, there can be a maximum of 8 electrons. While atoms may have multiple orbitals, they always want the outermost orbital to contain 8 electrons (inner orbitals would already have 8 electrons in them). Many atoms do not have 8 electrons in their outermost orbital, only certain elements do, you might know them as the noble gases. These elements have filled outer orbitals, and therefore do not react with any other element. Other elements, however, do not have filled orbitals, so when they come in contact with different atoms that could help them achieve these goals, the atoms share the electrons, and thus come together to form different compounds. The atoms are not just mindless building blocks; each element and the atoms that are of these elements have unique characteristics because of their electrons, and thus react with other elements.