Central sleep apnea is a breathing disorder that occurs during sleep and results when the brain fails to activate the respiratory muscles. This leads to a brief pause in breathing that may last 10 seconds or longer. Unlike the more standard obstructive sleep apnea - which is caused when the upper airway becomes temporarily obstructed - in central sleep apnea, the effort to breathe stops and there is no clear obstruction of the airway. Though the cause is slightly different, the outcome of central sleep apnea is the same.
Naming Inorganic Compounds. Binary Molecular Compounds. When a pair of elements form more than one type of covalent compound, Greek prefixes are used to indicate how many of each element are in a compound. The more electronegative element is written last and its ending is changed to ide.Examples.hen a pair of elements form more than one type of covalent compound, Greek prefixes are used to indicate how many of each element are in a compound.
1 Most crystals are ionic compounds. 2  This is because the ions in these compounds tend to stack into crystal lattices to balance between the attractive forces between opposite ions and the repulsive forces between like ions. 3  Covalent or molecular compounds can exist as crystals, though. Ionic compounds tend to have higher melting and boiling points than covalent compounds. 2  Ionic compounds tend to be hard and brittle while covalent compounds tend to be softer and more flexible. 3  Ionic compounds conduct electricity when dissolved in water while covalent compounds typically don't.