Let $F$ be a finite field, $Sq^i$ be the $i$-th [Steenrod operation](https://ncatlab.org/nlab/show/Steenrod+square)

$$ H^*(-;F) \to H^{*+i}(-;F).$$

By Yoneda lemma, such operation is a map $\phi_i: B^{*}F \to B^{*+i} F$, where $B$ denotes the [delooping operator](https://ncatlab.org/nlab/show/delooping). By applying its inverse $\Omega$ many times, we get a map $\psi_i: \Omega^iF \to F$. I would like to understand Steenrod operation $Sq^i$ by $\psi_i$.

1. Can you describe $\psi_i$ explicitly?
2. What do Adem's relations translate to in this perspective? Can I see the combinatorics much clearly?
3. Can we generalize this construction from $F$ to all abelian groups? It seems to me that the crux hides in the natural transformation 

$$\Omega^i \to Id,$$

and does nothing with the coefficient system $F$.