The element "um" is what type of word element?

Asingle atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it? ok o z

Nitrogen (n), phosphorus (p), and potassium (k) are the main nutrients in plant fertilizers. according to an industry convention, the numbers on the label refer to the mass percents of n, p2o5, and k2o, in that order. calculate the n: p: k ratio of a 30: 10: 10 fertilizer in terms of moles of each element, and express it as x: y: 1.0.

What’s the percent by mass of carbon in c10h14n2