Reword this for meh !
the triassic follows the largest extinction event in the history of life, and so is a time when the survivors of that event spread and recolonized. the organisms of the triassic can be considered to belong to one of three groups: holdovers from the permo-triassic extinction, new groups which flourished briefly, and new groups which went on to dominate the mesozoic world.

What best explains whether bromine (br) or neon (ne) is more likely to form a covalent bond? bromine forms covalent bonds because it has seven valence electrons, but neon has eight valence electrons and already fulfills the octet rule. bromine forms covalent bonds because it has many electron shells, but neon has only two electron shells and is tightly bound to its electrons. neon forms covalent bonds because it can share its valence electrons, but bromine has seven valence electrons and can gain only one more electron. neon forms covalent bonds because it has only two electron shells, but bromine has many electron shells and will lose electrons in order to fulfill the octet rule.