Iodine has a lower atomic weight than tellurium (126.90 for I, 127.60 for Te) even though it has a higher atomic number (53 for I, 52 for Te). Explain.

Iodine has lower atomic weight than tellurium, because tellurium has the atomic weight 127.60 and tellurium has the atomic weight 126.90 which comes after the element tellurium and lighter atomic weight than the tellurium. In the Mendleeve's table iodine is come before tellurium because iodine has less atomic weight than tellurium.

Iodine has higher atomic number than tellurium, because the atomic number 53 with iodine is higher than tellurium with atomic number 52. The atomic number is defined as number of protons present in the nucleus, which determines the chemical properties of the elements.

Answer and Explanation:

Iodine have lower atomic mass than tellurium even though the atomic number of iodine is more than the atomic number of tellurium

This is because the atomic weight of any element is the sum of number of proton and number of neutron, even though the number of proton in iodine is more so but the number of neutron is less as compared to tellurium which makes the tellurium of high atomic mass