Similar to all other chemical elements the uranium atom has protons, neutrons and electrons; uranium is also unstable and radioactive. Potters use uranium in their gaze to get a rich yellow colour.
Enriched uranium is still usually mainly 238U, but it has a higher percentage of 235U than the natural abundance.
Depleted uranium is exactly the opposite: it's got a LOWER than normal amount of...
Oxidize it. Burning is really easy. Acids (even water) will work too.
Solving of uranium in nitric acid, dilution with water, precipitation with ammonia (or other chemicals), first calcination to...