Can all energy be recycled?

yes, because energy cannot be destroyed
yes, because each energy conversion process is recycled energy
no, because the energy released from fuels loses its ability to perform work with each energy conversion

It is used to during sexual reproduction between humans

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass

Yes yes yes very good