_chemistry_is_world_

Select the correct✅ option.

𝐂𝐇𝐄𝐌𝐈𝐒𝐓𝐑𝐘 𝐈𝐒 𝐖𝐎𝐑𝐋𝐃

Select the correct✅ option.

𝐂𝐇𝐄𝐌𝐈𝐒𝐓𝐑𝐘 𝐈𝐒 𝐖𝐎𝐑𝐋𝐃

Radioactive substance.

Uranium.

Uranium (U) has atomic number 92, so every uranium isotope contains 92 protons. Isotopes differ in their number of neutrons.
The three best-known naturally occurring uranium isotopes are:
Isotope
Protons
Neutrons
Approx. natural abundance
Half-life
Uranium-238 (²³⁸U)
92
146
99.27%
~4.47 billion years
Uranium-235 (²³⁵U)
92
143
0.72%
~704 million years
Uranium-234 (²³⁴U)
92
142
~0.0055%
~246,000 years
All uranium isotopes are radioactive. U-238 is by far the most abundant, while U-235 is especially important in nuclear energy because it is fissile, meaning it can sustain a nuclear fission chain reaction.