Ionic compound are those compounds which are made up of ions. The ion which has tendency to loose electrons is said to cation (positive charge) such as metals whereas ion which has tendency to gain electrons is said to anion (negative charge) such as non-metals.
Calcium nitrate is quite soluble in water due to very low lattice enthalpy in comparison to other ionic compound. With lower lattice enthalpy, less energy is required for the dissociation of calcium nitrate and it get dissolves in water than other three compounds. Moreover, hydration energy is higher for calcium nitrate which make its solubility higher in water than other ionic species.
Thus, 
is correct answer.
The mass of ore required is
21 700 t.
r = 750 cm
V =
=
= 1.767 × 10⁹ cm³
The density of lead is 11.34 g/cm³.
So mass of lead sphere = 1.767 × 10⁹ cm³ ×
= 2.004 ×10¹⁰ g
2.004 ×10¹⁰ g ×
= 2.004 × 10⁷ kg
2.004 × 10⁷ kg ×
= 2.004 × 10⁴ t
92.5% efficiency means 92.5 t Pb per 100 t of ore.
Mass of ore = 2.004 × 10⁴ t Pb ×
= 2.17 × 10⁴ t ore = 21 700 t ore
<span>Salt is the product formed by a reaction in which the hydrogen atoms of an acid are replaced by the atoms of a metal. The salt is formed as a result of the neutralization of the acid by base, that is the metal or positive ion replace the hydrogen ion in the acid. For instance: NaO + H2SO4 = NaSO4 + H2O. In this example, Na [sodium] has replaced the hydrogen in H2SO4, thereby forming the salt NaSO4.</span>
Positrons are spontaneously emitted from the nuclei of potassium -37.
