Explain why Zinc, although it is a transition metal is monovalent

Apeak with a retention time of 407 s has a width at half-height (w1/2) of 7.6 s. a neighboring peak is eluted 17 s later with a w1/2 of 9.4 s. a compound that is known not to be retained was eluted in 2.5 s. the peaks are not baseline resolved. how many theoretical plates would be needed to achieve a resolution of 1.5?

What are the two largest greenhouse gases

Citric acid has a ph between 1 and 3.  it is considered to be aa. weak acidb. weak basec. strong based. strong acid