How many oxygen atoms are in 30 molecules of c20h42s3o2?

There are 2 atoms in one molecule 

So there are 30 x 2 = 60

Hope this helps.

Because it was a dramatically big guy

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