How do atoms achieve noble gas electron configurations in single covalent bonds

Calculate the number of molecules present in 0.750 mol of mgo.

What is i fracture in the crust called when land move up, down or sideways

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?