When aqueous solutions of lead(ii) nitrate and potassium iodide are mixed, what is the formula for the insoluble solid (precipitate) that forms?

The formula for the precipitate is PbI₂

Explanation:

The chemical reaction is:

Pb(NO₃)₂ (aq)  +  2KI (aq)  →  2KNO₃ (aq) + PbI₂ (s)↓

All the iodides, with these cations (Ag⁺, Pb²⁺, Cu⁺, Hg²⁺, Bi⁺³ and Sn⁺⁴) produce insolubles solid.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms