AQA GCSE Writing nuclear fission equations

Writing nuclear fission equations for induced fission.

In induced fission, a neutron will collide with a nucleus and then split into two daughter nuclei, produce 2 or 3 neutrons and release energy.

Lets start with induced fission of U-235, by writing the reactants. 

The neutron is on the left, Uranium 235 is adjacent, the atomic number of 92 can be found from the periodic table. Then put an arrow to the right of both of them.

Now we need to write down the daughter nuclei that will be formed to the right of the arrow. The exact nuclei that form are not important, but they should be roughly the same size. I have selected Barium-131 and Krypton-92

What is important, it to check the atomic numbers. So the 56 and 36 should add up to 92. Remember to look up the symbols, using the atomic numbers.

The mass numbers of 92 and 141 will add up to 233. The U-235 + 1 neutron gives a total mass number of 236. So, we are 3 mass numbers short, this is because we need to add of 3 neutrons being produced. See below:

Energy is always released, so energy is just added on. Remember the energy is released, not produced

It is unlikely you will be building these equations from scratch, but you may have to fill in one blank. See the practice questions below