Which of the following are included in group 8a (sometimes referred to as group 18)? check all that apply. a. helium b. xenon c. potassium d. argon

The right options are;

A. Helium

B. Xenon

D. Argon

Group 8A elements of the periodic table are the noble gases which include helium, neon, argon, krypton, xenon, and radon.  These elements are inert or unreactive towards other elements or compounds because they have full set of valence electrons. They are colorless, odorless, and tasteless monatomic gases when they are at room temperature. They also have low boiling and melting points.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."