What is the melting temperature of magnesium in kelvin

Why is nh3 classified as a polar molecule

The atomic number, or number, is the described as the number of in the nucleus of an chemical element.

Aroom with dimensions 7.00m×8.00m×2.50m is to be filled with pure oxygen at 22.0∘c and 1.00 atm. the molar mass of oxygen is 32.0 g/mol. how many moles noxygen of oxygen are required to fill the room? what is the mass moxygen of this oxygen?