Would a precipitate form if a solution contained 8.0 x 10-4 m silver nitrate and 1.8 x 10-4 m potassium chromate? you will have to find ksp values from your text or from another source.

Chemical reaction: 2Ag⁺(aq) + CrO₄²⁻(aq) → Ag₂CrO₄(s).
Ksp(Ag₂CrO₄) = 1,1·10⁻¹².
[Ag⁺] = c(AgNO₃) = 8.0·10⁻⁴ M.
[CrO₄²⁻] = c(K₂CrO₄) = 1.8·10⁻⁴ M.
Q(Ag₂CrO₄) = [Ag⁺]²·[CrO₄²⁻]. 
Q = (8.0·10⁻⁴ M)² · 1.8·10⁻⁴ M.
Q = 1.152·10⁻¹⁰.
Q > Ksp, a precipitate of silver chromate will form.
Ksp is the solubility product constant for a solid substance dissolving in an aqueous solution.

[Ag⁺] is equilibrium concentration of silver cations.
[CrO₄²⁻] is equilibrium concentration of chromate anions.

If a substance is solid at room temperature, has a crystalline structure, dissolves easily in water and conduce electricity well, then such a substance contains AN IONIC BOND.

Ionic compound and covalent compounds are formed in different ways, ionic bonds are formed by donation of electrons while covalent bonds are formed by sharing of electrons, due to this fact, the compounds containing these two chemical bonds have different distinguishing properties.

All the properties given in the question above are characteristics of ionic compounds; the only exception is the state of matter of the substance. Just like ionic compounds, covalent compounds too can be solid at room temperature. But covalent compound can not conduct electricity and they do not have crystalline structure.