Which one is the incorrect statement regarding mass spectrum?   options:   The (M)+• peak may be weak or entirely absent if it is particularly susceptible to fragmentation.   The tallest peak in a mass spectrum is assigned a relative value of 100% and is called the base peak which always represent molecular ion, (M)+•   According to nitrogen rule, an odd molecular weight indicates an odd number of nitrogen atoms, while an even molecular weight indicates either the absence of nitrogen or an even number of nitrogen atoms   Mass spectrum shows the relative abundance of each cation detected   The (M)+• peak indicates the molecular weight of the molecule

A mixture of species of A and B is injected into a liquid chromatographic column with length of 20.0 cm. The obtained separation results are listed as follows: Species Retention time (min) Peak Width at Base (min) Non-retained 3.0 A 5.2 0.48 В 5.9 0.56 From the data, the calculated resolution Rs is smaller than 1.5 for A and B when the column length is 20.0 cm, which indicates that A and B are not separate completely. What is the new column length (unit: cm) necessary to separate the A and B species with a good resolution Rs = 1.5? Please keep your answer to one decimal place.

Can you please explain how to solve this problem?

if you perform a 1:5 dilution of a 1 M solution , how many parts of the 1 M solution do you use, and how many parts of the diluent do you use?