Complex sleep apnea is the term used to describe a form of sleep disordered breathing in which repeated central apneas (>5/hour) persist or emerge when obstructive events are extinguished with positive airway pressure (PAP) and for which there is not a clear cause for the central apneas such as narcotics or systolic heart failure.
Giant covalent structures. Such as silicon dioxide, have extremely high melting points and low solubility in all solvents. They are non-volatile and conductivity depends on the availability of electrons in the valence shell (eg graphite). If all electrons are used in bonding they are insulators.ow melting points:- The bonds between molecules are very weak, especially when the molecules are small. It only requires a small quantity of heat energy to create enough molecular vibration to break the molecules attraction for one another and the solid melts.
The best answer I can come up with is that covalent molecular are held together by covalent bonds AND intermolecular bonds whereas covalent networks are only held together by â¦ covalent bonds. This means that the intermolecular bonds in covalent molecular are easy to break which is why it has a low boiling point. Covalent networks are all covalently bonded which means they are stronger and have a higher boiling point. I hope that's right because i have a test on this tomorrow. Sorry if it is wrong.