What's the difference between first half-life and second half-life?

What are the options? i can you if you give them.

Deposition is the transition of matter going from gas to solid without passing through the liquid phase.a.) gas—-> solid

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