Of the 8 causes of Trench mouth that we have listed, we have the following prevalence/incidence information: 1  1 causes are very common diseases. 2  0 causes are common diseases. 3  0 causes are uncommon diseases.  0 causes are rare 1  diseases. 0 causes are very rare diseases.  7 causes have no prevalence information.
An Ionic compound consists of a bond between a metal and a nonmetal element. So the answer would be ..... Ionic compounds are usually formed when a metal reacts with a nonmetal. So the answers would be c. and d. because lithium is a metal, chlorines a nonmetal , sodiums a metal iodines a nonmetal.
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.