Oxygen, sulfur, nitrogen, and hydrogen!
Pure water is very close to a pH of 7. The Great Salt Lake (from what I've read about) can range from 8.2 to 7.7 in different areas. Saliva is between 6.5 and 7.5. And ammonia has a pH of 11.
So the items that have a pH between 5 and 8 are pure water, saliva, and possibly the Great Salt Lake.
Hazardous substances are dangerous substances while toxins are poisonous substances. Hazardous substances may cause harm to an individuals health; they include acute toxins such as cyanide; substances harmful after repeated or prolonged exposure such as mercury and silica, among others. Toxic substances can be poisonous or cause health effects.
For the answer to the question above,
<span>DNA is made up of two nucleotide strands. The nucleotides are connected together by covalent bonds within each strand. The sugar of one nucleotide forms a covalent bond with the phosphate group of another. The two strands themselves are connected by hydrogen bonds. The hydrogen bonds are found between the bases of the two strands of nucleotides. Adenine forms hydrogen bonds with thymine whereas guanine forms hydrogen bonds with cytosine. This is called complementary base pairing</span>