" An element with atomic number "21" is a: "

The element with atomic number 1 is

The element with atomic numbers 19 is

Element with atomic number 16 is _____

The element with an atomic number 26 is

The ratio of wavelength of K_alpha line of an element with atomic number 61 to wavelength of K_alpha line of an element with atomic number 21 is

Write the electronic configurations for the elements with atomic number 15, 21 and 37. To which blocks in the periodic table do these elements belong ?