About 25 of the 92 natural elements are known to be essential to life. which four of these 25 elements make up approximately 96% of living matter? about 25 of the 92 natural elements are known to be essential to life. which four of these 25 elements make up approximately 96% of living matter? carbon, oxygen, phosphorus, hydrogen carbon, hydrogen, nitrogen, oxygen carbon, oxygen, nitrogen, calcium oxygen, hydrogen, calcium, nitrogen carbon, sodium, hydrogen, nitrogen