PLEASE HELP ME IDENTIFY THIS ELEMENT

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions

X-rays are used instead of visible light because x-rays have shorter than visible light, allowing them to produce images of much greater detail. a) energies b) frequencies c) speeds d) wavelengths

Which is an example of a mixture? a. water b. trail mix c. hydrogen d.carbon dioxide