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.
âº Metalloids form covalent hydrides that are volatile. âº Some metalloids (boron, silicon, arsenic, and selenium) can form organometallic compounds, which are compounds that contain covalent bonds between a metal and carbon atoms. This was some basic information related to the properties of metalloids.etalloids in the periodic table include Boron (B), Silicon (Si), Germanium (Ge), Arsenic (Ar), Antimony (Sb), and Tellurium (Te). Here are the general physical properties exhibited by metalloids. Refer to the images inside the boxes, for the electronic configuration of each.