The kind of Uranium used in atomic bombs like "Little boy" dropped in the Japanese city of Hiroshima is Uranium 235.
-It has 92 protons therefore its proton number is 92
-It has 143 neutrons in the nucleus.
-The 92 protons + 143 neutrons make 235, so its nucleon number is 235.
Other important information.
- Its atomic number, which is determined by the number of protons in the nucleus is 92 since it has 92 protons in its nucleus.
- Atomic mass is 238.0289 amu
- number of electrons is 92
- number of energy levels is 7