an element has a half-life of 5.0 days. How many days would pass before only 1/8th of the original amount of a sample of this element remained

You would do 1500/4 and the answer is 375

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

Heating it up with cause a quicker reaction time

D. h2o + h2o > h3o + oh- confirmed.