10 facts about neutrons

Hi sweeties <3 Alexandra's been sick since Wednesday, poor girl, so I've spent most of the time taking care of her and comfort her. Therefore, again (!), this week's Friday Facts blogpost comes on a Sunday. Hope you understand...
This time I feel the need of giving you ten facts about my favourite particle - the neutron:

1. neutrons are radioactive if they are "free" (alone, and not part of the nucleus of an atom)
2. neutrons have no charge - they are neutral, and can therefore "sneak" into another nucleus, and for example make it fission :D
3. the recipe for a neutron is: 2 down quarks and 1 up quark (opposite to the proton that is made up of 2 ups and 1 down)
4. the half-life of a (free) neutron is about 10.2 minutes, and then it turns into a proton, and electron, and an anti neutrino. Meaning it beta decays :D
5. the neutron was discovered by James Chadwick in 1932
6. neutrons have a mass, which is almost equal to the proton, but the neutron is a little bit heavier. Actually the mass of the neutron is 1.674927471×10⁻²⁷ kg (or 0.00000000000000000000000000164927471 kg), and that's the same as 2.5 electron masses (electrons weigh really little) more than a proton
7. neutrons can make stuff radioactive - which is called neutron activation; so a normal, stable gold nucleus can for example be activated by a neutron and go from gold-197 (stable) into gold-198 (un stable) and then decay into mercury-198, which is stable
8. you can't make a nucleus entirely out of neutrons - you have to have at least one proton too, and then you have deuteron, or heavy hydrogen
9. number 8 is actually just sort of true; you can go to an extreme, and calculate how many neutrons you need to make a "nucleus" entirely out of neutrons (since neutrons have no charge, they don't repel each other, like protons do, but they don't stick together either - a little bit like two pieces of paper; if you put them together they will just fall apart), and since they do have a mass they will attract each other because of gravity between them. This means that if you have enough neutrons, you will make something that won't just fall apart; and that number is . Not exactly nuclear size...:P (Read more about that HERE)
10. when neutrons hit you, they will give you a dose that is dependant on their energy. The highest dose from a neutron comes when it has an energy of 1 million electron volts. If the neutron has lower or higher energy, the dose from it will be lower. 

For some reason I imagine neutrons to be white :P How do you imagine the neutron to look?