Uranium 235 and uranium 238 are isotope are chemically different why?

Answer 1

An isotope means an atom with the same amount of electrons and protons, but with different amount of neutrons.

Relative weight of a neutron is 1, a proton is 1, and an electron is very small. So weight of an atom is approx. mneutrons + m protons.

So, an uranium-235, as U is the 92th atom in Periodic Table, contains 92 protons, 92 electrons to be chargeless, and 143 (=235-92) neutrons.

An uranium-238, from the definition of isotope, contains 92 protons, 92 electrons, and 146 (=238-92) neutrons.

The difference is the 3 neutrons.

Answer 2

The atomic number of uranium is 92, which means that all uranium atoms have 92 protons in their nuclei. They differ in the number of neutrons. Atoms of U-235 have 92 protons and 143 neutrons in their nuclei. Atoms of U-238 have 92 protons and 146 neutrons in their nuclei.

Answer 3

Uranium-235 and uranium-238 are isotopes of each other because they have the same number of protons but a different number of neutrons in their nuclei. The slight difference in mass due to the differing number of neutrons affects their chemical behavior, with uranium-235 being slightly lighter and therefore exhibiting some differences in chemical reactions compared to uranium-238.

Answer 4

Uranium-235 has 143 neutrons and uranium-238 has 146 neutrons.

Answer 5

Uranium 235 is fissionable with thermal neutrons, uranium 238 practically not. Some details at: http://nuclearweaponarchive.org/Library/Fission.html

Answer 6

U-238 has three neutrons more than U-235.