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.
Hydrochloric acid is usually purchased in a concentrated form that is 37.0% HCl by mass and has a density of 1.20g/mL. Calculate the molarity of the concd HCl.
1.20 g/mL x 1000 mL x 0.37 x (1/36.5) = about 12 M or so but you do it exactly.
Then mL x M = mL x M
mL x 12 M = 2800 mL x 0.475
Solve for mL of the concd HCl solution.
Density = mass / volume
Density = (45g) / (9 [volume units])
Density = 5g / [volume unit]
There was no specification on the units of volume. However, whatever it may be, just replace the square brackets with the value and your units will be correct.
Answer: D. Ecologist
Explanation: an ecologist is someone who studies the interactions of different organisms. An ecologist would be a type of scientist who would most likely study the interactions of birds
Iron should be in the 3d block
