FOR CHEMISTRY GODS:The number of molecules per cubic metre of air at standard temperature and pressure is about 2.7×10²⁵ m-3. What is the average separation of these molecules.

Ahypothrticalax type of ceramic material is known to have a density of 2.10 g/cm3 and a unit cell of cubic symmetry with a cell edge length of 0.57 nm. the atomic weights of the a and x elements are 28.5and 30.0 g/mol, respectively. on the basis of this information, which of the following crystal structures is (are) possible for this material: sodium chloride, cesium chloride, or zinc blende

The pressure inside a hydrogen-filled container was 2.10 atm at 21 ? c. what would the pressure be if the container was heated to 92 ? c ?

Name the element in group 17, period 2. (periodic table)