Complete the ff equation, which represented a nuclear fission reaction .what is the particle represented by 235U+0^1n=b+139Cs+2x+energy

X?

The missing particle represented by X is 87Br.

The complete equation for the nuclear fission reaction is:

235U + 0n → 139Cs + 87Br + 2(1n) + energy

The particle represented by "2x" in the equation 235U + 0^1n = b + 139Cs + 2x + energy is 2 neutrons (2n).