In real solutions, each ion is surrounded by an ionic atmosphere of particles of the opposite sign. The ionic atmosphere impedes the movement of the ion and prevents its chemical interaction, as a result of which the concentration of ions that actually manifest themselves in action (active concentration) is less than their true concentration.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.