What is the R group in the amino acid serine?

You may expect bonds between two atoms which each have n covalent lonic metallic hydrogen

Which of the following words describe the reality that the universe looks the same from various perspective

The solid xy decomposes into gaseous x and y: xy(s) m x(g) + y(g) kp = 4.1 (at 0 °c) if the reaction is carried out in a 22.4 l container, which initial amounts of x and y will result in the formation of solid xy?