Which pair of atoms would form a covalent bond ?
calcium (ca) and bromine (br)
rubidium (rb) and sulfur (s)
cesium (cs) and nitrogen (n)
oxygen (o) and chlorine (cl)

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.