What determines if elements will combine?

The ability of elements to combine is determined primarily by their electron configuration, particularly the number of valence electrons. Atoms tend to seek stability by achieving a full outer electron shell, often through chemical bonding, which can occur via ionic or covalent interactions. Additionally, factors such as electronegativity, atomic size, and the presence of functional groups influence how and whether elements will combine. Overall, these properties dictate the likelihood and type of bonds that can form between different elements.