What is not a guideline required for a valid evidence test?

A. The test must be conducted by a forensic scientist in a forensics lab.

B. The test must be reproducible, producing the same results every time using the same samples.

C. The test must be specific to identify a particular substance.

D. The test must be sensitive in that it can pick out the unique characteristics in a sample

H tricky one let me think and get back to u

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.

#2- the hno3 has a h+ ion and the naoh has an oh- ion