desertification, urbanization, and climate change(more carbon dioxide).
Atoms in covalent bonds do combine so as to be stable. As covalent bond consist non metals e.g O2 in this example each atom has vacance of 2 orbitals/ electrons so shairing electrons result their stability
Metalloids are metallic-looking brittle solids<span> that are either semiconductors or exist in semiconducting forms, and have amphoteric or weakly acidic oxides. Typical </span>nonmetals<span> have a </span>dull<span>, coloured or colourless </span>appearance<span>; are </span>brittle<span> when </span>solid<span>; are poor conductors of heat and electricity; and have acidic oxides.</span>