A sample of element $\mathrm{X}$ contains $69\%$ of ${}^{63}\mathrm{X}$ and $31\%$ of ${}^{65}\mathrm{X}$. What is the relative atomic mass of $\mathrm{X}$ in this sample?

What is the relative atomic mass of an element with the mass spectrum shown in figure?

List the following types of electromagnetic radiation in order of increasing wavelength (shortest first).

I. Yellow light

II. Red light

III. Infrared radiation

IV. Ultraviolet radiation.