Elements in the same group of the periodic table have the same number of in their highest occupied energy level. What word completes the sentence?​

They are all full and don't need any more electrons in there outer shell.

The mass has escaped into a gas which you can not see so the law stays true.

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy

What are the choices?