Question

Which type of reaction occurs in the core of a nuclear reactor in a nuclear power plant?
Upper H upper C l plus upper N a upper O upper H right arrow upper H subscript 2 upper O plus upper n a upper C l.
Superscript 235 subscript 92 upper U plus superscript 1 subscript 0 n right arrow superscript 90 subscript 38 upper S r plus superscript 143 subscript 54 upper X e plus 3 superscript 1 subscript 0 n.
Superscript 90 subscript 38 upper S r plus superscript 143 subscript 54 upper X e plus 3 superscript 1 subscript 0 n right arrow superscript 235 subscript 92 upper U plus superscript 1 subscript 0 n.
Upper C subscript 10 upper h subscript 8 plus 12 upper O subscript 2 right arrow 10 upper C upper O subscript 2 plus 4 upper H subscript 2 upper O.

Answer 1

The reaction in a nuclear reactor core is the nuclear fission of uranium:
superscript 235 subscript 92 U + superscript 1 subscript 0 n → superscript 90 subscript 38 Sr + superscript 143 subscript 54 Xe + 3 superscript 1 subscript 0 n

This is nuclear fission: a heavy nucleus (U‑235) absorbs a neutron, splits into lighter fission fragments and releases additional neutrons and a large amount of energy. Those released neutrons sustain a controlled chain reaction in the reactor core.

(For completeness: HCl + NaOH → H2O + NaCl is an acid–base neutralization; C10H8 + 12 O2 → 10 CO2 + 4 H2O is combustion. The third line as written would be the reverse of fission and does not represent the process occurring in reactors.)