All living organisms, together with carbon 12 / 6C, assimilate the radioactive isotope 14 / 6C. The content of radioactive carbon in the air remains constant for many millennia. After the death of a living organism, its decay begins. Knowing the half-life of radioactive carbon, its percentage during the life of the organism and measuring it at the time of detection, it is possible to calculate the age of the fossil remains.
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.