How might a sudden cold front limit population growth of newborn offspring?"" HELP PLEASE

In this assignment, you will analyze an example of speciation by researching the finches of the galapagos islands. then you will answer questions to construct explanations and draw conclusions based on the information you gather. someone plz !

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.

Which of these is not a nucleotide base found in dna?