Solid compounds

Binary compounds are created with all nonmetallic elements, several through direct combination. Beryllium is special because its coordination is almost all the time tetrahedral, providing structures which may be considered as polymeric rather than highly ionic. So. BeO has the wurtzite structure, BeF₂ is identical to SiO₂, and BeCl₂ (such as SiS₂) has a chain structure (3) based on edge-sharing tetrahedra. BeH₂ is the same with bridging hydrogens creating three-center bonds like in B₂H₆.

The remaining elements' compounds have structures more in line with the expectations of the ionic model. Oxides MO all comprise the rocksalt structure; like the cation size increases they turn into increasingly basic and reactive in the direction of water and CO₂, providing M(OH)₂ or MCO₃, correspondingly. Peroxides like BaO₂ are formed through the heavier elements in the group. Halides depict increasing coordination with size, 6 for Mg and 7 or eight for the larger ions. MgF₂ comprise the rutile structure and the another MF₂ compounds the fluorite structure. Heavier halides of Mg provide layer structures (CdCl₂ and CdI₂) where for the larger cations rather distorted structures are created (example distorted rutile for CaCl₂); these show to be dictated through the tendency to asymmetrical coordination of the halide ion, with cations very large to create general layer structures. Fluorides (particularly CaF₂) have low solubility in water, but other halides are very soluble.

Binary compounds with less electronegative elements comprise sulfides, hydrides, nitrides, and phosphides. They are decomposed through water and can give convenient routes for the preparation of nonmetal hydrides . The anions might be polymerized or polyatomic, like with CaC₂, that contains C₂^2- and reacts with water to provide acetylene (ethyne) C₂H₂.

The elements create an enormous variety of compounds with oxoanions, several of those with calcium (carbonate, silicate, phosphate, sulfate) being general minerals in the Earth's crust. Hydrated forms are general. Their thermal stability in the direction of decomposition to the oxide is less than that for the alkali metals, and rises with cation size. So Be (such as Al) does not create a stable carbonate; the decomposition temperatures for the others range to 1400°C for BaCO₃ from 400°C for MgCO₃. These trends can be observed by using lattice energy arguments.