1 Free jazz almost by definition is free of such structures, but also by definition (it is, after all, jazz as much as it is free) it retains much of the language of earlier jazz playing. 2  It is therefore very common to hear diatonic, altered dominant and blues phrases in this music.
The main overall nuclear fusion reaction is the fusion of four hydrogen atom nuclei to form a bigger nucleus of a helium atom i.e. 4 1H1 $\rightarrow$ 4He2 + 2 0e+1+ energyi.e., 4 Hydrogen nuclei -----> Helium nucleus + 2 positrons + energy.
The  most common example of nuclear fusion is when two types of (known  as isotopes of) hydrogen fuse together to create helium. The  isotopes of hydrogen deuterium and tritium fuse to create helium.  Deuterium contains one proton and one neutron and tritium contains  two neutrons and one proton.