You're asking about the masses of uranium and uranium oxide. It's important to specify which uranium oxide you're interested in because there are several common ones:

* Uranium dioxide (UO₂): This is the most common form used in nuclear reactors.

* Uranium trioxide (UO₃): This is an intermediate product in the production of nuclear fuel.

* Uranium tetroxide (UO₄): This is a highly reactive and unstable compound.

Here's how to calculate the masses of these compounds:

1. Find the atomic mass of uranium (U):

* The atomic mass of uranium is approximately 238.03 g/mol.

2. Find the atomic mass of oxygen (O):

* The atomic mass of oxygen is approximately 16.00 g/mol.

3. Calculate the molar mass of each uranium oxide:

* UO₂: (238.03 g/mol) + 2 * (16.00 g/mol) = 270.03 g/mol

* UO₃: (238.03 g/mol) + 3 * (16.00 g/mol) = 286.03 g/mol

* UO₄: (238.03 g/mol) + 4 * (16.00 g/mol) = 302.03 g/mol

Therefore:

* The mass of one mole of uranium is 238.03 g.

* The mass of one mole of uranium dioxide (UO₂) is 270.03 g.

* The mass of one mole of uranium trioxide (UO₃) is 286.03 g.

* The mass of one mole of uranium tetroxide (UO₄) is 302.03 g.

Remember: These are the masses of one mole of each substance. To calculate the mass of a different quantity, you would multiply the molar mass by the desired number of moles.