So there are three isotopes of Carbon that can exist in nature.
The e- flies out with a tremendous amount of energy, collides with something (turning it's energy of motion into heat).
Earth rocks and soil of similar types as the lunar samples may be provided and explored with hands, eyes, noses, and tools! Show the Lunar Sample Disk to the children and explain that these rocks and "soil" are actual samples that were brought back from the Moon by Apollo astronauts!
Children can see snapshots of the Moon's history and hold an important artifact of American history with a Lunar Sample Disk.
Notably, the neutrons do not change the chemical behavior of the atom.
A carbon atom will not hold together unless it has at least 6 neutrons (i.e., Carbon-11 does not exist because the repulsive force is too strong). If we try to make C-15 (with 9 neutrons), it falls apart immediately also.