Uranium is a radioactive metal found in minerals.
Uses and research
Certain isotopes are used as fuel in nuclear reactors.
Learning from radioactive elements
The actinides form the lower detached row. None has a stable isotope. Isotopes have the same proton count but different neutron counts. Some actinides occur in natural minerals; others are available only in tiny research samples. When discussing uses or behavior, the particular isotope can matter.
What the atomic number tells us
Uranium has atomic number 92. This is the number of protons in its nucleus. A neutral atom also has 92 electrons. Losing or gaining electrons makes an ion; it does not change the element unless the proton count changes.
The model's rings help count electrons by shell. They are not actual circular paths. A model of one atom and the properties of a whole material are different levels of description.
Temperature and state
25°C: Solid
Illustrative particle motion: sizes, distances and speeds are not to scale. Particles represent atoms or molecules.
← CoolHeat →
Melting point 1,134.85°C / Boiling point 4,130.85°C
Pure element at 1 atmosphere. Image conditions are explained in captions. Pictures do not change with temperature.