Pioneer species are the first species to arrive in an area after succession (hope this helped because i dont know about climax communities)
The question is incomplete. The complete question is:
Calcium Carbide (CaC₂) is an unusual substance that contains a carbon anion (C₂²⁻). The reaction with water involves several steps that occur in rapid succession. CaC2 is a salt (notice that its name is similar to sodium chloride). When a salt dissolves in water, ions leave the crystal lattice and enter the aqueous (aq) solution. Write the relevant balanced chemical equation for the dissolution of CaC₂, in water.
Answer:
CaC₂(s) + 2H₂O(l) → Ca(OH)₂(aq) + C₂H₂(aq)
Explanation:
When a salt dissolves in water, it dissociates in its ions. In the Calcium Carbide, the cation is Ca⁺² and the anion is C₂²⁻, so the reaction is:
CaC₂(s) + 2H₂O(l) → Ca(OH)₂(aq) + C₂H₂(aq)
The base Ca(OH)₂ is soluble, so it will dissociate at Ca⁺ and OH⁻, but the C₂H₂ is stable and doesn't dissociate in the solution.
The two of them both made models of the current atom, which was very excellent because now we could imagine how an atom would look. I would say that the best one was the electron orbital configuration because we needed to know what valence electrons are.