Whose work directly resulted in the development of and atomic model that has negative electrons stuck within a sea of positive materials

Write a balanced equation showing the formation of copper (ii) nitrite from its elements

Why must humans find substitutes for many minerals found on earth? (a) form at an extremely slow rate (b) controlled by other countries (c) too deep in the earth to collect

Awhite powder is added to a solution. the images show observations made before the powder is added, just after the powder has been added, and a little while later. (the liquid in the small beaker is phenol red solution.) what evidence shows that a chemical change has taken place?