The question incomplete , the complete question is:
A student dissolves of 18.0 g urea in 200.0 mL of a solvent with a density of 0.95 g/mL . The student notices that the volume of the solvent does not change when the urea dissolves in it. Calculate the molarity and molality of the student's solution. Round both of your answers to significant digits.
Answer:
The molarity and molality of the student's solution is 1.50 Molar and 1.58 molal.
Explanation:
Moles of urea = 
Volume of the solution = 200.0 mL = 0.2 L (1 mL = 0.001 L)

Molarity of the urea solution ;

Mass of solvent = m
Volume of solvent = V = 200.0 mL
Density of the urea = d = 0.95 g/mL


(1 g = 0.001 kg)
Molality of the urea solution ;


The molarity and molality of the student's solution is 1.50 Molar and 1.58 molal.
The attachments dont work, they say that they have been taken down or sum... ?
The formula unit of compounds formed depends on the valency of the combining ions.
The formula unit is the smallest unit of an ionic substance that gives us a picture of the ratio in which ions are combined in the ionic compound.
Usually, the formula unit is written based on the valency of the ions.
For the ions listed;
Li+ and 02- forms Li2O
Mg2+ and S2- forms MgS
A13+ and CI- forms AlCl3
Na+ and N3- forms Na3N
Learn more: brainly.com/question/9743981