What's the amount of electrons on each electron shell

Each energy level (shell) has more subshells available to it: The first shell only has the s subshell ⟹ 2 electrons. The second shell has the s and p subshells ⟹ 2 + 6 = 8 electrons. The third shell has the s, p, and d subshells ⟹ 2 + 6 + 10 = 18 electrons.

You start with 2 on the inside and add two to each shell each time

The overall purpose of the light-dependent reactions is to convert light energy into chemical energy. This chemical energy will be used by the Calvin cycle to fuel the assembly of sugar molecules. The light-dependent reactions begin in a grouping of pigment molecules and proteins called a photosystem.

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