Molality is defined as 1 mole of a solute in 1 kg of solvent.
Molality=

Number of moles of solute, n=

Given mass of the nitrobenzene=0.2 g
Molar mass of the substance= 123.06 g mol⁻¹
Number of moles of nitrobenzene,

Number of moles of nitrobenzene, n= 0.0016 mol
Mass of 10.9 g of naphthalene in kg=0.0109

Molality= 0.146 m
Physical properties include: appearance, texture, color, boiling point, melting point, ect.
A solution is a homogeneous mixture, meaning it contains 2 or more substances. A solute is a substance that’s dissolved in the solvent. Think of it as dissolving salt (solute) in water (solvent) to make a salt solution. The amount of each substance in the solution impacts the concentration of it. So if I put more salt than water, it increases its concentration, while adding more water decreases its concentration.
If the solution is BASIC than it will turn purple but if ACIDIC it will turn pink.
It also depends on what we use to make the energy in the power plants. Many use uranium which is non renewable. A better alternative would be wind or solar as it is always around. Hope this helps.