The correct term is tenacity, with c. It is the quality of the tenacious. It is the strength, commitment or zeal with which it decides to do something, without giving up. It means firmness, persistence, insistence, resistance, adhesion, consistency, perseverance, berraquero. The degree of cohesion of particles in physics is, therefore it is the degree of resistance from effects of an impact. Ability to absorb shock.