Calculate the average of 1, 3, 5, 7, 9, 11, 13, 15 and 17.
As we know, average of first n odd numbers = n. Here, n = 9 ∴ Required average = 9
(a) What are radioactive isotopes ? Give two examples of radioactive isotopes.
(b) Give any two uses of radioactive isotopes.
(c) An element Z contains two naturally occurring isotopes 3517Z and 3717Z. If the average atomic mass of this element be 35.5 u, calculate the percentage of two isotopes.