Copper reacts with nitric acid releasing nitrogen dioxide gas. Why is this answer
right?

Achemistry student weighs out of phosphoric acid , a triprotic acid, into a volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with solution. calculate the volume of solution the student will need to add to reach the final equivalence point. round your answer to significant digits.

Compare and contrast physical changes with chemical changes.

Give the orbital configuration of the phosphorus (p) atom.