While most constellations are only visible to us in different seasons, some are always there 24/7/365 because they are positioned close to the Polar Axis, or the Polaris.
The reagent which limits the reaction is called limiting reagents.
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For example:- N2+3H2gives 2NH3.so here nitrogen limits the reaction.
I'm not sure what the question is, this is a lab proecdure
4Na +2e- ---->2Na2
O2 +2e- ------>2O
