Sodium reacts with chlorine react to produce sodium chloride that is familiarly called table salt.
2Na(s) + Cl2(g) ——> 2NaCl(s)
The reaction may look very simple. But, it is extremely exothermic, producing a bright yellow light and a great amount of heat energy.
Bassam Z. Shakhashiri, Chemical Demonstrations: A Handbook for Teachers of Chemistry, Volume 1. Madison: The University of Wisconsin Press, 1983, p. 61-63.
Lee R. Summerlin, Christie L. Borgford, and Julie B. Ealy, Chemical Demonstrations: A Sourcebook for Teachers, Volume 2, 2nd ed. Washington, D.C.: American Chemical Society, 1988, p. 56-57.