In the ground state, the valence electrons of a krypton atom are found in 1. The first shell
2. The outermost shell
3. Both the nucleus and the first shell
4. Both the first shell and the outermost shell

2. The outermost shell

Explanation:

In an elements ground state, its electrons have the least amount of energy that they could have so they stay in their shells. When Krypton is in this state therefore, its valence electrons will stay in the outermost shell.

As Krypton has a total of 36 electrons in this state, there will be 8 valence electrons and they will all be in the outer shell.

- aluminum and copper chloride.

- the chloride ion to separate the aluminum from the oxygen so that the aluminum can react with the copper ions (and the water molecules).

there is none because earth is stationary and flat.