How many valence electrons do the alkaline earth metals have?

How many neutrons does a atom of cobalt have?

Classify this reaction: 2al+n2-> aln.

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?