There are ________ number of known elements.

The atomic number of an element is 9. It has 10 neutrons. Find the element from the periodic table. What will be its mass number?

If a set A has n elements, then the total number of subset of A or the number of elements in the power set of A

If the elements with principal quantum number n gt 4 did not exist in nature the number of possible element would be ________ .

If in nature there may not be an element for which the principal quantum number n > 6, then the total possible number of elements will be

If A is a radioactive element which emits an alpha -particle and produces ""_104Rf^(259) . Write the atomic number and mass number of the element A.

_________ and ______ properties of the elements are the periodic function of their _______ numbers.