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
Answer:
I'm sure it's option A. Cast Fossil
Answer: C
Explanation:
The one closest to the atomic center, there is a single 1s orbital that can hold 2 electrons. At the next energy level, there are four orbitals.
The appropriate answer is b. greenhouse gases. Greenhouse gases such as carbon dioxide and methane have the ability to trap infrared radiation or heat in the atmosphere. Without these gases the Earth would be thirty degrees cooler than it is today. Pollution today has caused more of these gases to enter the atmosphere and this is the main cause of contemporary global warming.
Ozone in the stratosphere actually blocks another form of radiation called ultraviolet radiation. Geothermal energy is derived from hot rocks inside the earth.