Why is it not possible to have a 2d orbital but a 3d orbital is allowed?​

What is the overall order of reaction for rate = k[no]2[o2]

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

In 2002, the rare earth elements mine in mountain pass, california was closed because