During prophase, chromatin condenses into chromosomes, and the nuclear envelope, or membrane, breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles (sides) of the cell.
It’s the longest phase of mitosis. when the nucleus divides, the two chromatids that make up each chromosome separate from each other and move to opposite poles of the cell
Light. When an electron falls to a lower orbit it gives off energy as a photon. Spectral lines give evidence of electrons moving from one energy level to another within the atom.
