Why are factory effluents harmful to aquatic
organisms?

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

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

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.