Suppose that in a 2-dimensional crystallization process with only one substance, the nuclei do not all appear simultaneously, but rather appear uniformly over space and time at rate λ (nuclei per unit area per unit tim). a crystal only starts growing when the nucleus appears. adapt the k-a model to this situation: i. e., find φ(t). hints: work in a 3-dimensional space (2 dimensions of space and one of ti). consider an arbitrary point p in this space (arbitrary location, arbitrary time). determine the region, r, in this 3-dimensional space in which a nucleus must appear in order for p to lie inside the circle growing from the nucleus. then follow question 3 above.